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https://git.openldap.org/openldap/openldap.git
synced 2024-12-21 03:10:25 +08:00
2408 lines
57 KiB
C
2408 lines
57 KiB
C
#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/queue.h>
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#include <sys/param.h>
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#include <sys/uio.h>
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#include <sys/mman.h>
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#ifdef HAVE_SYS_FILE_H
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#include <sys/file.h>
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#endif
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#include <sys/ipc.h>
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#include <sys/shm.h>
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#include <assert.h>
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#include <err.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <stddef.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <time.h>
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#include <unistd.h>
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#include <pthread.h>
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#include "mdb.h"
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#define DEBUG
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#ifdef DEBUG
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# define DPRINTF(...) do { fprintf(stderr, "%s:%d: ", __func__, __LINE__); \
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fprintf(stderr, __VA_ARGS__); \
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fprintf(stderr, "\n"); } while(0)
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#else
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# define DPRINTF(...)
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#endif
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#define PAGESIZE 4096
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#define MDB_MINKEYS 4
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#define MDB_MAGIC 0xBEEFC0DE
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#define MDB_VERSION 1
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#define MAXKEYSIZE 255
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#define P_INVALID (~0L)
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#define F_ISSET(w, f) (((w) & (f)) == (f))
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typedef ulong pgno_t;
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typedef uint16_t indx_t;
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#define DEFAULT_READERS 126
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#define DEFAULT_MAPSIZE 1048576
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/* Lock descriptor stuff */
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#define RXBODY \
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ulong mr_txnid; \
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pid_t mr_pid; \
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pthread_t mr_tid
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typedef struct MDB_rxbody {
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RXBODY;
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} MDB_rxbody;
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#ifndef CACHELINE
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#define CACHELINE 64 /* most CPUs. Itanium uses 128 */
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#endif
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typedef struct MDB_reader {
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RXBODY;
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/* cache line alignment */
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char pad[CACHELINE-sizeof(MDB_rxbody)];
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} MDB_reader;
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#define TXBODY \
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uint32_t mt_magic; \
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uint32_t mt_version; \
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pthread_mutex_t mt_mutex; \
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ulong mt_txnid; \
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uint32_t mt_numreaders
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typedef struct MDB_txbody {
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TXBODY;
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} MDB_txbody;
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typedef struct MDB_txninfo {
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TXBODY;
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char pad[CACHELINE-sizeof(MDB_txbody)];
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pthread_mutex_t mt_wmutex;
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char pad2[CACHELINE-sizeof(pthread_mutex_t)];
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MDB_reader mt_readers[1];
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} MDB_txninfo;
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/* Common header for all page types. Overflow pages
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* occupy a number of contiguous pages with no
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* headers on any page after the first.
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*/
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typedef struct MDB_page { /* represents a page of storage */
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pgno_t mp_pgno; /* page number */
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#define P_BRANCH 0x01 /* branch page */
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#define P_LEAF 0x02 /* leaf page */
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#define P_OVERFLOW 0x04 /* overflow page */
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#define P_META 0x08 /* meta page */
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#define P_HEAD 0x10 /* header page */
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#define P_DIRTY 0x20 /* dirty page */
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uint32_t mp_flags;
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#define mp_lower mp_pb.pb.pb_lower
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#define mp_upper mp_pb.pb.pb_upper
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#define mp_pages mp_pb.pb_pages
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union page_bounds {
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struct {
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indx_t pb_lower; /* lower bound of free space */
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indx_t pb_upper; /* upper bound of free space */
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} pb;
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uint32_t pb_pages; /* number of overflow pages */
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} mp_pb;
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indx_t mp_ptrs[1]; /* dynamic size */
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} MDB_page;
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#define PAGEHDRSZ offsetof(MDB_page, mp_ptrs)
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#define NUMKEYS(p) (((p)->mp_lower - PAGEHDRSZ) >> 1)
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#define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
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#define PAGEFILL(env, p) (1000 * ((env)->me_head.mh_psize - PAGEHDRSZ - SIZELEFT(p)) / \
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((env)->me_head.mh_psize - PAGEHDRSZ))
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#define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF)
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#define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
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#define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
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typedef struct MDB_head { /* header page content */
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uint32_t mh_magic;
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uint32_t mh_version;
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uint32_t mh_flags;
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uint32_t mh_psize; /* page size */
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void *mh_address; /* address for fixed mapping */
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size_t mh_mapsize; /* size of mmap region */
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} MDB_head;
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typedef struct MDB_meta { /* meta (footer) page content */
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MDB_stat mm_stat;
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pgno_t mm_root; /* page number of root page */
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pgno_t mm_last_pg; /* last used page in file */
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ulong mm_txnid; /* txnid that committed this page */
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} MDB_meta;
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typedef struct MDB_dhead { /* a dirty page */
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SIMPLEQ_ENTRY(MDB_dpage) md_next; /* queue of dirty pages */
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MDB_page *md_parent;
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int md_pi; /* parent index */
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int md_num;
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} MDB_dhead;
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typedef struct MDB_dpage {
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MDB_dhead h;
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MDB_page p;
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} MDB_dpage;
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SIMPLEQ_HEAD(dirty_queue, MDB_dpage);
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typedef struct MDB_pageparent {
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MDB_page *mp_page;
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MDB_page *mp_parent;
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int mp_pi;
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} MDB_pageparent;
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static MDB_dpage *mdb_newpage(MDB_txn *txn, MDB_page *parent, int parent_idx, int num);
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static int mdb_touch(MDB_txn *txn, MDB_pageparent *mp);
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typedef struct MDB_ppage { /* ordered list of pages */
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SLIST_ENTRY(MDB_ppage) mp_entry;
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MDB_page *mp_page;
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unsigned int mp_ki; /* cursor index on page */
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} MDB_ppage;
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SLIST_HEAD(page_stack, MDB_ppage);
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#define CURSOR_EMPTY(c) SLIST_EMPTY(&(c)->mc_stack)
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#define CURSOR_TOP(c) SLIST_FIRST(&(c)->mc_stack)
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#define CURSOR_POP(c) SLIST_REMOVE_HEAD(&(c)->mc_stack, mp_entry)
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#define CURSOR_PUSH(c,p) SLIST_INSERT_HEAD(&(c)->mc_stack, p, mp_entry)
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struct MDB_cursor {
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MDB_db *mc_db;
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MDB_txn *mc_txn;
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struct page_stack mc_stack; /* stack of parent pages */
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short mc_initialized; /* 1 if initialized */
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short mc_eof; /* 1 if end is reached */
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};
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#define METAHASHLEN offsetof(MDB_meta, mm_hash)
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#define METADATA(p) ((void *)((char *)p + PAGEHDRSZ))
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typedef struct MDB_node {
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#define mn_pgno mn_p.np_pgno
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#define mn_dsize mn_p.np_dsize
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union {
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pgno_t np_pgno; /* child page number */
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uint32_t np_dsize; /* leaf data size */
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} mn_p;
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uint16_t mn_ksize; /* key size */
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#define F_BIGDATA 0x01 /* data put on overflow page */
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uint8_t mn_flags;
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char mn_data[1];
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} MDB_node;
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struct MDB_txn {
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pgno_t mt_root; /* current / new root page */
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pgno_t mt_next_pgno; /* next unallocated page */
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pgno_t mt_first_pgno;
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ulong mt_txnid;
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MDB_env *mt_env;
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union {
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struct dirty_queue *dirty_queue; /* modified pages */
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MDB_reader *reader;
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} mt_u;
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#define MDB_TXN_RDONLY 0x01 /* read-only transaction */
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#define MDB_TXN_ERROR 0x02 /* an error has occurred */
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unsigned int mt_flags;
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};
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/* Must be same as MDB_db, minus md_root/md_stat */
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typedef struct MDB_db0 {
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unsigned int md_flags;
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MDB_cmp_func *md_cmp; /* user compare function */
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MDB_rel_func *md_rel; /* user relocate function */
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MDB_db *md_parent; /* parent tree */
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MDB_env *md_env;
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} MDB_db0;
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struct MDB_db {
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unsigned int md_flags;
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MDB_cmp_func *md_cmp; /* user compare function */
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MDB_rel_func *md_rel; /* user relocate function */
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MDB_db *md_parent; /* parent tree */
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MDB_env *md_env;
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MDB_stat md_stat;
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pgno_t md_root; /* page number of root page */
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};
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struct MDB_env {
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int me_fd;
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key_t me_shmkey;
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uint32_t me_flags;
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int me_maxreaders;
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int me_metatoggle;
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char *me_path;
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char *me_map;
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MDB_txninfo *me_txns;
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MDB_head me_head;
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MDB_db0 me_db; /* first DB, overlaps with meta */
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MDB_meta me_meta;
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MDB_txn *me_txn; /* current write transaction */
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size_t me_mapsize;
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off_t me_size; /* current file size */
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pthread_key_t me_txkey; /* thread-key for readers */
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};
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#define NODESIZE offsetof(MDB_node, mn_data)
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#define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
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#define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
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#define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i]))
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#define NODEKEY(node) (void *)((node)->mn_data)
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#define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
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#define NODEPGNO(node) ((node)->mn_pgno)
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#define NODEDSZ(node) ((node)->mn_dsize)
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#define MDB_COMMIT_PAGES 64 /* max number of pages to write in one commit */
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#define MDB_MAXCACHE_DEF 1024 /* max number of pages to keep in cache */
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static int mdb_search_page_root(MDB_db *db,
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MDB_val *key,
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MDB_cursor *cursor, int modify,
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MDB_pageparent *mpp);
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static int mdb_search_page(MDB_db *db,
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MDB_txn *txn, MDB_val *key,
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MDB_cursor *cursor, int modify,
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MDB_pageparent *mpp);
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static int mdbenv_write_header(MDB_env *env);
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static int mdbenv_read_header(MDB_env *env);
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static int mdb_check_meta_page(MDB_page *p);
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static int mdbenv_read_meta(MDB_env *env);
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static int mdbenv_write_meta(MDB_txn *txn);
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static MDB_page *mdbenv_get_page(MDB_env *env, pgno_t pgno);
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static MDB_node *mdb_search_node(MDB_db *db, MDB_page *mp,
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MDB_val *key, int *exactp, unsigned int *kip);
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static int mdb_add_node(MDB_db *bt, MDB_page *mp,
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indx_t indx, MDB_val *key, MDB_val *data,
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pgno_t pgno, uint8_t flags);
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static void mdb_del_node(MDB_db *bt, MDB_page *mp,
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indx_t indx);
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static int mdb_read_data(MDB_db *bt, MDB_page *mp,
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MDB_node *leaf, MDB_val *data);
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static int mdb_rebalance(MDB_db *bt, MDB_pageparent *mp);
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static int mdb_update_key(MDB_db *bt, MDB_page *mp,
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indx_t indx, MDB_val *key);
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static int mdb_move_node(MDB_db *bt,
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MDB_pageparent *src, indx_t srcindx,
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MDB_pageparent *dst, indx_t dstindx);
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static int mdb_merge(MDB_db *bt, MDB_pageparent *src,
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MDB_pageparent *dst);
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static int mdb_split(MDB_db *bt, MDB_page **mpp,
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unsigned int *newindxp, MDB_val *newkey,
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MDB_val *newdata, pgno_t newpgno);
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static MDB_dpage *mdbenv_new_page(MDB_env *env, uint32_t flags, int num);
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static void cursor_pop_page(MDB_cursor *cursor);
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static MDB_ppage *cursor_push_page(MDB_cursor *cursor,
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MDB_page *mp);
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static int mdb_set_key(MDB_db *bt, MDB_page *mp,
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MDB_node *node, MDB_val *key);
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static int mdb_sibling(MDB_cursor *cursor, int move_right);
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static int mdb_cursor_next(MDB_cursor *cursor,
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MDB_val *key, MDB_val *data);
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static int mdb_cursor_set(MDB_cursor *cursor,
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MDB_val *key, MDB_val *data, int *exactp);
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static int mdb_cursor_first(MDB_cursor *cursor,
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MDB_val *key, MDB_val *data);
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static size_t mdb_leaf_size(MDB_db *bt, MDB_val *key,
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MDB_val *data);
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static size_t mdb_branch_size(MDB_db *bt, MDB_val *key);
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static pgno_t mdbenv_compact_tree(MDB_env *env, pgno_t pgno,
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MDB_env *envc);
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static int memncmp(const void *s1, size_t n1,
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const void *s2, size_t n2);
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static int memnrcmp(const void *s1, size_t n1,
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const void *s2, size_t n2);
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static int
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memncmp(const void *s1, size_t n1, const void *s2, size_t n2)
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{
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if (n1 < n2) {
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if (memcmp(s1, s2, n1) == 0)
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return -1;
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}
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else if (n1 > n2) {
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if (memcmp(s1, s2, n2) == 0)
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return 1;
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}
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return memcmp(s1, s2, n1);
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}
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static int
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memnrcmp(const void *s1, size_t n1, const void *s2, size_t n2)
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{
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const unsigned char *p1;
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const unsigned char *p2;
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if (n1 == 0)
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return n2 == 0 ? 0 : -1;
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if (n2 == 0)
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return n1 == 0 ? 0 : 1;
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p1 = (const unsigned char *)s1 + n1 - 1;
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p2 = (const unsigned char *)s2 + n2 - 1;
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while (*p1 == *p2) {
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if (p1 == s1)
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return (p2 == s2) ? 0 : -1;
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if (p2 == s2)
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return (p1 == p2) ? 0 : 1;
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p1--;
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p2--;
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}
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return *p1 - *p2;
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}
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int
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mdb_cmp(MDB_db *db, const MDB_val *a, const MDB_val *b)
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{
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return db->md_cmp(a, b);
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}
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static int
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_mdb_cmp(MDB_db *db, const MDB_val *key1, const MDB_val *key2)
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{
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if (F_ISSET(db->md_flags, MDB_REVERSEKEY))
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return memnrcmp(key1->mv_data, key1->mv_size, key2->mv_data, key2->mv_size);
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else
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return memncmp((char *)key1->mv_data, key1->mv_size, key2->mv_data, key2->mv_size);
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}
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/* Allocate new page(s) for writing */
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static MDB_dpage *
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mdb_newpage(MDB_txn *txn, MDB_page *parent, int parent_idx, int num)
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{
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MDB_dpage *dp;
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if ((dp = malloc(txn->mt_env->me_head.mh_psize * num + sizeof(MDB_dhead))) == NULL)
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return NULL;
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dp->h.md_num = num;
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dp->h.md_parent = parent;
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dp->h.md_pi = parent_idx;
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SIMPLEQ_INSERT_TAIL(txn->mt_u.dirty_queue, dp, h.md_next);
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dp->p.mp_pgno = txn->mt_next_pgno;
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txn->mt_next_pgno += num;
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return dp;
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}
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/* Touch a page: make it dirty and re-insert into tree with updated pgno.
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*/
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static int
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mdb_touch(MDB_txn *txn, MDB_pageparent *pp)
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{
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int rc;
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MDB_page *mp = pp->mp_page;
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pgno_t pgno;
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assert(txn != NULL);
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assert(pp != NULL);
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if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
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MDB_dpage *dp;
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DPRINTF("touching page %lu -> %lu", mp->mp_pgno, txn->mt_next_pgno);
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if ((dp = mdb_newpage(txn, pp->mp_parent, pp->mp_pi, 1)) == NULL)
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return ENOMEM;
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pgno = dp->p.mp_pgno;
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bcopy(mp, &dp->p, txn->mt_env->me_head.mh_psize);
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mp = &dp->p;
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mp->mp_pgno = pgno;
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mp->mp_flags |= P_DIRTY;
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/* Update the page number to new touched page. */
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if (pp->mp_parent != NULL)
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NODEPGNO(NODEPTR(pp->mp_parent, pp->mp_pi)) = mp->mp_pgno;
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pp->mp_page = mp;
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}
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return 0;
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}
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int
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mdbenv_sync(MDB_env *env)
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{
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int rc = 0;
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if (!F_ISSET(env->me_flags, MDB_NOSYNC)) {
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if (fsync(env->me_fd))
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rc = errno;
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}
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return rc;
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}
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int
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mdb_txn_begin(MDB_env *env, int rdonly, MDB_txn **ret)
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{
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MDB_txn *txn;
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int rc;
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if ((txn = calloc(1, sizeof(*txn))) == NULL) {
|
|
DPRINTF("calloc: %s", strerror(errno));
|
|
return ENOMEM;
|
|
}
|
|
|
|
if (rdonly) {
|
|
txn->mt_flags |= MDB_TXN_RDONLY;
|
|
} else {
|
|
txn->mt_u.dirty_queue = calloc(1, sizeof(*txn->mt_u.dirty_queue));
|
|
if (txn->mt_u.dirty_queue == NULL) {
|
|
free(txn);
|
|
return ENOMEM;
|
|
}
|
|
SIMPLEQ_INIT(txn->mt_u.dirty_queue);
|
|
|
|
pthread_mutex_lock(&env->me_txns->mt_wmutex);
|
|
env->me_txns->mt_txnid++;
|
|
}
|
|
txn->mt_txnid = env->me_txns->mt_txnid;
|
|
if (rdonly) {
|
|
MDB_reader *r = pthread_getspecific(env->me_txkey);
|
|
if (!r) {
|
|
int i;
|
|
pthread_mutex_lock(&env->me_txns->mt_mutex);
|
|
for (i=0; i<env->me_maxreaders; i++) {
|
|
if (env->me_txns->mt_readers[i].mr_pid == 0) {
|
|
env->me_txns->mt_readers[i].mr_pid = getpid();
|
|
env->me_txns->mt_readers[i].mr_tid = pthread_self();
|
|
pthread_setspecific(env->me_txkey, &env->me_txns->mt_readers[i]);
|
|
if (i >= env->me_txns->mt_numreaders)
|
|
env->me_txns->mt_numreaders = i+1;
|
|
break;
|
|
}
|
|
}
|
|
pthread_mutex_unlock(&env->me_txns->mt_mutex);
|
|
if (i == env->me_maxreaders) {
|
|
return ENOSPC;
|
|
}
|
|
}
|
|
r->mr_txnid = txn->mt_txnid;
|
|
txn->mt_u.reader = r;
|
|
} else {
|
|
env->me_txn = txn;
|
|
}
|
|
|
|
txn->mt_env = env;
|
|
|
|
if ((rc = mdbenv_read_meta(env)) != MDB_SUCCESS) {
|
|
mdb_txn_abort(txn);
|
|
return rc;
|
|
}
|
|
|
|
txn->mt_next_pgno = env->me_meta.mm_last_pg+1;
|
|
txn->mt_first_pgno = txn->mt_next_pgno;
|
|
txn->mt_root = env->me_meta.mm_root;
|
|
DPRINTF("begin transaction %lu on mdbenv %p, root page %lu", txn->mt_txnid, env, txn->mt_root);
|
|
|
|
*ret = txn;
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
void
|
|
mdb_txn_abort(MDB_txn *txn)
|
|
{
|
|
MDB_dpage *dp;
|
|
MDB_env *env;
|
|
|
|
if (txn == NULL)
|
|
return;
|
|
|
|
env = txn->mt_env;
|
|
DPRINTF("abort transaction %lu on mdbenv %p, root page %lu", txn->mt_txnid, env, txn->mt_root);
|
|
|
|
if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
|
|
txn->mt_u.reader->mr_txnid = 0;
|
|
} else {
|
|
/* Discard all dirty pages.
|
|
*/
|
|
while (!SIMPLEQ_EMPTY(txn->mt_u.dirty_queue)) {
|
|
dp = SIMPLEQ_FIRST(txn->mt_u.dirty_queue);
|
|
SIMPLEQ_REMOVE_HEAD(txn->mt_u.dirty_queue, h.md_next);
|
|
free(dp);
|
|
}
|
|
|
|
#if 0
|
|
DPRINTF("releasing write lock on txn %p", txn);
|
|
txn->bt->txn = NULL;
|
|
if (flock(txn->bt->fd, LOCK_UN) != 0) {
|
|
DPRINTF("failed to unlock fd %d: %s",
|
|
txn->bt->fd, strerror(errno));
|
|
}
|
|
#endif
|
|
free(txn->mt_u.dirty_queue);
|
|
env->me_txn = NULL;
|
|
pthread_mutex_unlock(&env->me_txns->mt_wmutex);
|
|
}
|
|
|
|
free(txn);
|
|
}
|
|
|
|
int
|
|
mdb_txn_commit(MDB_txn *txn)
|
|
{
|
|
int n, done;
|
|
ssize_t rc;
|
|
off_t size;
|
|
MDB_dpage *dp;
|
|
MDB_env *env;
|
|
pgno_t next;
|
|
struct iovec iov[MDB_COMMIT_PAGES];
|
|
|
|
assert(txn != NULL);
|
|
assert(txn->mt_env != NULL);
|
|
|
|
env = txn->mt_env;
|
|
|
|
if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
|
|
DPRINTF("attempt to commit read-only transaction");
|
|
mdb_txn_abort(txn);
|
|
return EPERM;
|
|
}
|
|
|
|
if (txn != env->me_txn) {
|
|
DPRINTF("attempt to commit unknown transaction");
|
|
mdb_txn_abort(txn);
|
|
return EINVAL;
|
|
}
|
|
|
|
if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
|
|
DPRINTF("error flag is set, can't commit");
|
|
mdb_txn_abort(txn);
|
|
return EINVAL;
|
|
}
|
|
|
|
if (SIMPLEQ_EMPTY(txn->mt_u.dirty_queue))
|
|
goto done;
|
|
|
|
DPRINTF("committing transaction %lu on mdbenv %p, root page %lu",
|
|
txn->mt_txnid, env, txn->mt_root);
|
|
|
|
/* Commit up to MDB_COMMIT_PAGES dirty pages to disk until done.
|
|
*/
|
|
next = 0;
|
|
do {
|
|
n = 0;
|
|
done = 1;
|
|
size = 0;
|
|
SIMPLEQ_FOREACH(dp, txn->mt_u.dirty_queue, h.md_next) {
|
|
if (dp->p.mp_pgno != next) {
|
|
lseek(env->me_fd, dp->p.mp_pgno * env->me_head.mh_psize, SEEK_SET);
|
|
next = dp->p.mp_pgno;
|
|
if (n)
|
|
break;
|
|
}
|
|
DPRINTF("committing page %lu", dp->p.mp_pgno);
|
|
iov[n].iov_len = env->me_head.mh_psize * dp->h.md_num;
|
|
iov[n].iov_base = &dp->p;
|
|
size += iov[n].iov_len;
|
|
next = dp->p.mp_pgno + dp->h.md_num;
|
|
/* clear dirty flag */
|
|
dp->p.mp_flags &= ~P_DIRTY;
|
|
if (++n >= MDB_COMMIT_PAGES) {
|
|
done = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (n == 0)
|
|
break;
|
|
|
|
DPRINTF("committing %u dirty pages", n);
|
|
rc = writev(env->me_fd, iov, n);
|
|
if (rc != size) {
|
|
n = errno;
|
|
if (rc > 0)
|
|
DPRINTF("short write, filesystem full?");
|
|
else
|
|
DPRINTF("writev: %s", strerror(errno));
|
|
mdb_txn_abort(txn);
|
|
return n;
|
|
}
|
|
|
|
/* Drop the dirty pages.
|
|
*/
|
|
while (!SIMPLEQ_EMPTY(txn->mt_u.dirty_queue)) {
|
|
dp = SIMPLEQ_FIRST(txn->mt_u.dirty_queue);
|
|
SIMPLEQ_REMOVE_HEAD(txn->mt_u.dirty_queue, h.md_next);
|
|
free(dp);
|
|
if (--n == 0)
|
|
break;
|
|
}
|
|
} while (!done);
|
|
|
|
if ((n = mdbenv_sync(env)) != 0 ||
|
|
(n = mdbenv_write_meta(txn)) != MDB_SUCCESS ||
|
|
(n = mdbenv_sync(env)) != 0) {
|
|
mdb_txn_abort(txn);
|
|
return n;
|
|
}
|
|
env->me_txn = NULL;
|
|
pthread_mutex_unlock(&env->me_txns->mt_wmutex);
|
|
free(txn->mt_u.dirty_queue);
|
|
free(txn);
|
|
txn = NULL;
|
|
|
|
done:
|
|
mdb_txn_abort(txn);
|
|
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
static int
|
|
mdbenv_write_header(MDB_env *env)
|
|
{
|
|
struct stat sb;
|
|
MDB_head *h;
|
|
MDB_page *p;
|
|
ssize_t rc;
|
|
unsigned int psize;
|
|
|
|
DPRINTF("writing header page");
|
|
assert(env != NULL);
|
|
|
|
psize = sysconf(_SC_PAGE_SIZE);
|
|
|
|
if ((p = calloc(1, psize)) == NULL)
|
|
return ENOMEM;
|
|
p->mp_flags = P_HEAD;
|
|
|
|
env->me_head.mh_psize = psize;
|
|
env->me_head.mh_flags = env->me_flags & 0xffff;
|
|
|
|
h = METADATA(p);
|
|
bcopy(&env->me_head, h, sizeof(*h));
|
|
|
|
rc = write(env->me_fd, p, env->me_head.mh_psize);
|
|
free(p);
|
|
if (rc != (ssize_t)env->me_head.mh_psize) {
|
|
int err = errno;
|
|
if (rc > 0)
|
|
DPRINTF("short write, filesystem full?");
|
|
return err;
|
|
}
|
|
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
static int
|
|
mdbenv_read_header(MDB_env *env)
|
|
{
|
|
char page[PAGESIZE];
|
|
MDB_page *p;
|
|
MDB_head *h;
|
|
int rc;
|
|
|
|
assert(env != NULL);
|
|
|
|
/* We don't know the page size yet, so use a minimum value.
|
|
*/
|
|
|
|
if ((rc = pread(env->me_fd, page, PAGESIZE, 0)) == 0) {
|
|
return ENOENT;
|
|
} else if (rc != PAGESIZE) {
|
|
if (rc > 0)
|
|
errno = EINVAL;
|
|
DPRINTF("read: %s", strerror(errno));
|
|
return errno;
|
|
}
|
|
|
|
p = (MDB_page *)page;
|
|
|
|
if (!F_ISSET(p->mp_flags, P_HEAD)) {
|
|
DPRINTF("page %lu not a header page", p->mp_pgno);
|
|
return EINVAL;
|
|
}
|
|
|
|
h = METADATA(p);
|
|
if (h->mh_magic != MDB_MAGIC) {
|
|
DPRINTF("header has invalid magic");
|
|
return EINVAL;
|
|
}
|
|
|
|
if (h->mh_version != MDB_VERSION) {
|
|
DPRINTF("database is version %u, expected version %u",
|
|
h->mh_version, MDB_VERSION);
|
|
return EINVAL;
|
|
}
|
|
|
|
bcopy(h, &env->me_head, sizeof(*h));
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
mdbenv_init_meta(MDB_env *env)
|
|
{
|
|
MDB_page *p, *q;
|
|
MDB_meta *meta;
|
|
int rc;
|
|
|
|
p = calloc(2, env->me_head.mh_psize);
|
|
p->mp_pgno = 1;
|
|
p->mp_flags = P_META;
|
|
|
|
meta = METADATA(p);
|
|
meta->mm_root = P_INVALID;
|
|
meta->mm_last_pg = 2;
|
|
|
|
q = (MDB_page *)((char *)p + env->me_head.mh_psize);
|
|
|
|
q->mp_pgno = 2;
|
|
q->mp_flags = P_META;
|
|
|
|
meta = METADATA(q);
|
|
meta->mm_root = P_INVALID;
|
|
meta->mm_last_pg = 2;
|
|
|
|
rc = write(env->me_fd, p, env->me_head.mh_psize * 2);
|
|
free(p);
|
|
return (rc == env->me_head.mh_psize * 2) ? MDB_SUCCESS : errno;
|
|
}
|
|
|
|
static int
|
|
mdbenv_write_meta(MDB_txn *txn)
|
|
{
|
|
MDB_env *env;
|
|
MDB_meta meta;
|
|
off_t off;
|
|
int rc;
|
|
|
|
assert(txn != NULL);
|
|
assert(txn->mt_env != NULL);
|
|
|
|
DPRINTF("writing meta page for root page %lu", txn->mt_root);
|
|
|
|
env = txn->mt_env;
|
|
|
|
bcopy(&env->me_meta, &meta, sizeof(meta));
|
|
meta.mm_root = txn->mt_root;
|
|
meta.mm_last_pg = txn->mt_next_pgno - 1;
|
|
meta.mm_txnid = txn->mt_txnid;
|
|
|
|
off = env->me_head.mh_psize;
|
|
if (!env->me_metatoggle)
|
|
off *= 2;
|
|
off += PAGEHDRSZ;
|
|
|
|
lseek(env->me_fd, off, SEEK_SET);
|
|
rc = write(env->me_fd, &meta, sizeof(meta));
|
|
if (rc != sizeof(meta)) {
|
|
DPRINTF("write failed, disk error?");
|
|
return errno;
|
|
}
|
|
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
/* Returns true if page p is a valid meta page, false otherwise.
|
|
*/
|
|
static int
|
|
mdb_check_meta_page(MDB_page *p)
|
|
{
|
|
if (!F_ISSET(p->mp_flags, P_META)) {
|
|
DPRINTF("page %lu not a meta page", p->mp_pgno);
|
|
return EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
mdbenv_read_meta(MDB_env *env)
|
|
{
|
|
MDB_page *mp0, *mp1;
|
|
MDB_meta *meta[2];
|
|
int toggle = 0, rc;
|
|
|
|
assert(env != NULL);
|
|
|
|
if ((mp0 = mdbenv_get_page(env, 1)) == NULL ||
|
|
(mp1 = mdbenv_get_page(env, 2)) == NULL)
|
|
return EIO;
|
|
|
|
rc = mdb_check_meta_page(mp0);
|
|
if (rc) return rc;
|
|
|
|
rc = mdb_check_meta_page(mp1);
|
|
if (rc) return rc;
|
|
|
|
meta[0] = METADATA(mp0);
|
|
meta[1] = METADATA(mp1);
|
|
|
|
if (meta[0]->mm_txnid < meta[1]->mm_txnid)
|
|
toggle = 1;
|
|
|
|
if (meta[toggle]->mm_txnid > env->me_meta.mm_txnid) {
|
|
bcopy(meta[toggle], &env->me_meta, sizeof(env->me_meta));
|
|
env->me_metatoggle = toggle;
|
|
}
|
|
|
|
DPRINTF("Using meta page %d", toggle);
|
|
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
int
|
|
mdbenv_create(MDB_env **env)
|
|
{
|
|
MDB_env *e;
|
|
|
|
e = calloc(1, sizeof(*e));
|
|
if (!e) return ENOMEM;
|
|
|
|
e->me_head.mh_magic = MDB_MAGIC;
|
|
e->me_head.mh_version = MDB_VERSION;
|
|
e->me_head.mh_mapsize = DEFAULT_MAPSIZE;
|
|
e->me_maxreaders = DEFAULT_READERS;
|
|
e->me_db.md_env = e;
|
|
*env = e;
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
int
|
|
mdbenv_set_mapsize(MDB_env *env, size_t size)
|
|
{
|
|
if (env->me_map)
|
|
return EINVAL;
|
|
env->me_mapsize = env->me_head.mh_mapsize = size;
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
int
|
|
mdbenv_set_maxreaders(MDB_env *env, int readers)
|
|
{
|
|
env->me_maxreaders = readers;
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
int
|
|
mdbenv_get_maxreaders(MDB_env *env, int *readers)
|
|
{
|
|
if (!env || !readers)
|
|
return EINVAL;
|
|
*readers = env->me_maxreaders;
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
int
|
|
mdbenv_open2(MDB_env *env, unsigned int flags)
|
|
{
|
|
int i, newenv = 0;
|
|
|
|
env->me_flags = flags;
|
|
env->me_meta.mm_root = P_INVALID;
|
|
|
|
if ((i = mdbenv_read_header(env)) != 0) {
|
|
if (i != ENOENT)
|
|
return i;
|
|
DPRINTF("new mdbenv");
|
|
newenv = 1;
|
|
}
|
|
|
|
if (!env->me_mapsize)
|
|
env->me_mapsize = env->me_head.mh_mapsize;
|
|
|
|
i = MAP_SHARED;
|
|
if (env->me_head.mh_address && (flags & MDB_FIXEDMAP))
|
|
i |= MAP_FIXED;
|
|
env->me_map = mmap(env->me_head.mh_address, env->me_mapsize, PROT_READ, i,
|
|
env->me_fd, 0);
|
|
if (env->me_map == MAP_FAILED)
|
|
return errno;
|
|
|
|
if (newenv) {
|
|
env->me_head.mh_mapsize = env->me_mapsize;
|
|
if (flags & MDB_FIXEDMAP)
|
|
env->me_head.mh_address = env->me_map;
|
|
i = mdbenv_write_header(env);
|
|
if (i != MDB_SUCCESS) {
|
|
munmap(env->me_map, env->me_mapsize);
|
|
return i;
|
|
}
|
|
i = mdbenv_init_meta(env);
|
|
if (i != MDB_SUCCESS) {
|
|
munmap(env->me_map, env->me_mapsize);
|
|
return i;
|
|
}
|
|
}
|
|
|
|
if ((i = mdbenv_read_meta(env)) != 0)
|
|
return i;
|
|
|
|
DPRINTF("opened database version %u, pagesize %u",
|
|
env->me_head.mh_version, env->me_head.mh_psize);
|
|
DPRINTF("depth: %u", env->me_meta.mm_stat.ms_depth);
|
|
DPRINTF("entries: %lu", env->me_meta.mm_stat.ms_entries);
|
|
DPRINTF("branch pages: %lu", env->me_meta.mm_stat.ms_branch_pages);
|
|
DPRINTF("leaf pages: %lu", env->me_meta.mm_stat.ms_leaf_pages);
|
|
DPRINTF("overflow pages: %lu", env->me_meta.mm_stat.ms_overflow_pages);
|
|
DPRINTF("root: %lu", env->me_meta.mm_root);
|
|
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
static void
|
|
mdbenv_reader_dest(void *ptr)
|
|
{
|
|
MDB_reader *reader = ptr;
|
|
|
|
reader->mr_txnid = 0;
|
|
reader->mr_pid = 0;
|
|
reader->mr_tid = 0;
|
|
}
|
|
|
|
int
|
|
mdbenv_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode)
|
|
{
|
|
int oflags, rc, shmid;
|
|
off_t size;
|
|
|
|
|
|
if (F_ISSET(flags, MDB_RDONLY))
|
|
oflags = O_RDONLY;
|
|
else
|
|
oflags = O_RDWR | O_CREAT;
|
|
|
|
if ((env->me_fd = open(path, oflags, mode)) == -1)
|
|
return errno;
|
|
|
|
env->me_shmkey = ftok(path, 'm');
|
|
size = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
|
|
shmid = shmget(env->me_shmkey, size, IPC_CREAT|IPC_EXCL|mode);
|
|
if (shmid == -1) {
|
|
if (errno == EEXIST) {
|
|
shmid = shmget(env->me_shmkey, size, IPC_CREAT|mode);
|
|
if (shmid == -1)
|
|
return errno;
|
|
env->me_txns = shmat(shmid, NULL, 0);
|
|
if (env->me_txns->mt_magic != MDB_MAGIC ||
|
|
env->me_txns->mt_version != MDB_VERSION) {
|
|
DPRINTF("invalid lock region %d", shmid);
|
|
shmdt(env->me_txns);
|
|
env->me_txns = NULL;
|
|
return EIO;
|
|
}
|
|
} else {
|
|
return errno;
|
|
}
|
|
} else {
|
|
pthread_mutexattr_t mattr;
|
|
|
|
env->me_txns = shmat(shmid, NULL, 0);
|
|
pthread_mutexattr_init(&mattr);
|
|
pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
|
|
pthread_mutex_init(&env->me_txns->mt_mutex, &mattr);
|
|
pthread_mutex_init(&env->me_txns->mt_wmutex, &mattr);
|
|
env->me_txns->mt_version = MDB_VERSION;
|
|
env->me_txns->mt_magic = MDB_MAGIC;
|
|
}
|
|
|
|
if ((rc = mdbenv_open2(env, flags)) != MDB_SUCCESS) {
|
|
close(env->me_fd);
|
|
env->me_fd = -1;
|
|
} else {
|
|
env->me_path = strdup(path);
|
|
DPRINTF("opened dbenv %p", env);
|
|
}
|
|
|
|
pthread_key_create(&env->me_txkey, mdbenv_reader_dest);
|
|
|
|
return rc;
|
|
}
|
|
|
|
void
|
|
mdbenv_close(MDB_env *env)
|
|
{
|
|
if (env == NULL)
|
|
return;
|
|
|
|
free(env->me_path);
|
|
|
|
if (env->me_map) {
|
|
munmap(env->me_map, env->me_mapsize);
|
|
}
|
|
close(env->me_fd);
|
|
if (env->me_txns) {
|
|
shmdt(env->me_txns);
|
|
}
|
|
free(env);
|
|
}
|
|
|
|
/* Search for key within a leaf page, using binary search.
|
|
* Returns the smallest entry larger or equal to the key.
|
|
* If exactp is non-null, stores whether the found entry was an exact match
|
|
* in *exactp (1 or 0).
|
|
* If kip is non-null, stores the index of the found entry in *kip.
|
|
* If no entry larger or equal to the key is found, returns NULL.
|
|
*/
|
|
static MDB_node *
|
|
mdb_search_node(MDB_db *bt, MDB_page *mp, MDB_val *key,
|
|
int *exactp, unsigned int *kip)
|
|
{
|
|
unsigned int i = 0;
|
|
int low, high;
|
|
int rc = 0;
|
|
MDB_node *node;
|
|
MDB_val nodekey;
|
|
|
|
DPRINTF("searching %lu keys in %s page %lu",
|
|
NUMKEYS(mp),
|
|
IS_LEAF(mp) ? "leaf" : "branch",
|
|
mp->mp_pgno);
|
|
|
|
assert(NUMKEYS(mp) > 0);
|
|
|
|
bzero(&nodekey, sizeof(nodekey));
|
|
|
|
low = IS_LEAF(mp) ? 0 : 1;
|
|
high = NUMKEYS(mp) - 1;
|
|
while (low <= high) {
|
|
i = (low + high) >> 1;
|
|
node = NODEPTR(mp, i);
|
|
|
|
nodekey.mv_size = node->mn_ksize;
|
|
nodekey.mv_data = NODEKEY(node);
|
|
|
|
if (bt->md_cmp)
|
|
rc = bt->md_cmp(key, &nodekey);
|
|
else
|
|
rc = _mdb_cmp(bt, key, &nodekey);
|
|
|
|
if (IS_LEAF(mp))
|
|
DPRINTF("found leaf index %u [%.*s], rc = %i",
|
|
i, (int)nodekey.mv_size, (char *)nodekey.mv_data, rc);
|
|
else
|
|
DPRINTF("found branch index %u [%.*s -> %lu], rc = %i",
|
|
i, (int)node->mn_ksize, (char *)NODEKEY(node),
|
|
node->mn_pgno, rc);
|
|
|
|
if (rc == 0)
|
|
break;
|
|
if (rc > 0)
|
|
low = i + 1;
|
|
else
|
|
high = i - 1;
|
|
}
|
|
|
|
if (rc > 0) { /* Found entry is less than the key. */
|
|
i++; /* Skip to get the smallest entry larger than key. */
|
|
if (i >= NUMKEYS(mp))
|
|
/* There is no entry larger or equal to the key. */
|
|
return NULL;
|
|
}
|
|
if (exactp)
|
|
*exactp = (rc == 0);
|
|
if (kip) /* Store the key index if requested. */
|
|
*kip = i;
|
|
|
|
return NODEPTR(mp, i);
|
|
}
|
|
|
|
static void
|
|
cursor_pop_page(MDB_cursor *cursor)
|
|
{
|
|
MDB_ppage *top;
|
|
|
|
top = CURSOR_TOP(cursor);
|
|
CURSOR_POP(cursor);
|
|
|
|
DPRINTF("popped page %lu off cursor %p", top->mp_page->mp_pgno, cursor);
|
|
|
|
free(top);
|
|
}
|
|
|
|
static MDB_ppage *
|
|
cursor_push_page(MDB_cursor *cursor, MDB_page *mp)
|
|
{
|
|
MDB_ppage *ppage;
|
|
|
|
DPRINTF("pushing page %lu on cursor %p", mp->mp_pgno, cursor);
|
|
|
|
if ((ppage = calloc(1, sizeof(*ppage))) == NULL)
|
|
return NULL;
|
|
ppage->mp_page = mp;
|
|
CURSOR_PUSH(cursor, ppage);
|
|
return ppage;
|
|
}
|
|
|
|
static MDB_page *
|
|
mdbenv_get_page(MDB_env *env, pgno_t pgno)
|
|
{
|
|
MDB_page *p = NULL;
|
|
MDB_txn *txn = env->me_txn;
|
|
|
|
if (txn && pgno >= txn->mt_first_pgno &&
|
|
!SIMPLEQ_EMPTY(txn->mt_u.dirty_queue)) {
|
|
MDB_dpage *dp;
|
|
SIMPLEQ_FOREACH(dp, txn->mt_u.dirty_queue, h.md_next) {
|
|
if (dp->p.mp_pgno == pgno) {
|
|
p = &dp->p;
|
|
break;
|
|
}
|
|
}
|
|
} else {
|
|
p = (MDB_page *)(env->me_map + env->me_head.mh_psize * pgno);
|
|
}
|
|
return p;
|
|
}
|
|
|
|
static int
|
|
mdb_search_page_root(MDB_db *bt, MDB_val *key,
|
|
MDB_cursor *cursor, int modify, MDB_pageparent *mpp)
|
|
{
|
|
MDB_page *mp = mpp->mp_page;
|
|
int rc;
|
|
|
|
if (cursor && cursor_push_page(cursor, mp) == NULL)
|
|
return MDB_FAIL;
|
|
|
|
while (IS_BRANCH(mp)) {
|
|
unsigned int i = 0;
|
|
MDB_node *node;
|
|
|
|
DPRINTF("branch page %lu has %lu keys", mp->mp_pgno, NUMKEYS(mp));
|
|
assert(NUMKEYS(mp) > 1);
|
|
DPRINTF("found index 0 to page %lu", NODEPGNO(NODEPTR(mp, 0)));
|
|
|
|
if (key == NULL) /* Initialize cursor to first page. */
|
|
i = 0;
|
|
else {
|
|
int exact;
|
|
node = mdb_search_node(bt, mp, key, &exact, &i);
|
|
if (node == NULL)
|
|
i = NUMKEYS(mp) - 1;
|
|
else if (!exact) {
|
|
assert(i > 0);
|
|
i--;
|
|
}
|
|
}
|
|
|
|
if (key)
|
|
DPRINTF("following index %u for key %.*s",
|
|
i, (int)key->mv_size, (char *)key->mv_data);
|
|
assert(i >= 0 && i < NUMKEYS(mp));
|
|
node = NODEPTR(mp, i);
|
|
|
|
if (cursor)
|
|
CURSOR_TOP(cursor)->mp_ki = i;
|
|
|
|
mpp->mp_parent = mp;
|
|
if ((mp = mdbenv_get_page(bt->md_env, NODEPGNO(node))) == NULL)
|
|
return MDB_FAIL;
|
|
mpp->mp_pi = i;
|
|
mpp->mp_page = mp;
|
|
|
|
if (cursor && cursor_push_page(cursor, mp) == NULL)
|
|
return MDB_FAIL;
|
|
|
|
if (modify) {
|
|
MDB_dhead *dh = ((MDB_dhead *)mp)-1;
|
|
if (rc = mdb_touch(bt->md_env->me_txn, mpp))
|
|
return rc;
|
|
dh = ((MDB_dhead *)mpp->mp_page)-1;
|
|
dh->md_parent = mpp->mp_parent;
|
|
dh->md_pi = mpp->mp_pi;
|
|
}
|
|
|
|
mp = mpp->mp_page;
|
|
}
|
|
|
|
if (!IS_LEAF(mp)) {
|
|
DPRINTF("internal error, index points to a %02X page!?",
|
|
mp->mp_flags);
|
|
return MDB_FAIL;
|
|
}
|
|
|
|
DPRINTF("found leaf page %lu for key %.*s", mp->mp_pgno,
|
|
key ? (int)key->mv_size : 0, key ? (char *)key->mv_data : NULL);
|
|
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
/* Search for the page a given key should be in.
|
|
* Stores a pointer to the found page in *mpp.
|
|
* If key is NULL, search for the lowest page (used by mdb_cursor_first).
|
|
* If cursor is non-null, pushes parent pages on the cursor stack.
|
|
* If modify is true, visited pages are updated with new page numbers.
|
|
*/
|
|
static int
|
|
mdb_search_page(MDB_db *db, MDB_txn *txn, MDB_val *key,
|
|
MDB_cursor *cursor, int modify, MDB_pageparent *mpp)
|
|
{
|
|
int rc;
|
|
pgno_t root;
|
|
|
|
/* Can't modify pages outside a transaction. */
|
|
if (txn == NULL && modify) {
|
|
return EINVAL;
|
|
}
|
|
|
|
/* Choose which root page to start with. If a transaction is given
|
|
* use the root page from the transaction, otherwise read the last
|
|
* committed root page.
|
|
*/
|
|
if (txn == NULL) {
|
|
if ((rc = mdbenv_read_meta(db->md_env)) != MDB_SUCCESS)
|
|
return rc;
|
|
root = db->md_env->me_meta.mm_root;
|
|
} else if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
|
|
DPRINTF("transaction has failed, must abort");
|
|
return EINVAL;
|
|
} else
|
|
root = txn->mt_root;
|
|
|
|
if (root == P_INVALID) { /* Tree is empty. */
|
|
DPRINTF("tree is empty");
|
|
return ENOENT;
|
|
}
|
|
|
|
if ((mpp->mp_page = mdbenv_get_page(db->md_env, root)) == NULL)
|
|
return MDB_FAIL;
|
|
|
|
DPRINTF("root page has flags 0x%X", mpp->mp_page->mp_flags);
|
|
|
|
if (modify && !F_ISSET(mpp->mp_page->mp_flags, P_DIRTY)) {
|
|
mpp->mp_parent = NULL;
|
|
mpp->mp_pi = 0;
|
|
if ((rc = mdb_touch(txn, mpp)))
|
|
return rc;
|
|
txn->mt_root = mpp->mp_page->mp_pgno;
|
|
}
|
|
|
|
return mdb_search_page_root(db, key, cursor, modify, mpp);
|
|
}
|
|
|
|
static int
|
|
mdb_read_data(MDB_db *db, MDB_page *mp, MDB_node *leaf,
|
|
MDB_val *data)
|
|
{
|
|
MDB_page *omp; /* overflow mpage */
|
|
size_t psz;
|
|
size_t max;
|
|
size_t sz = 0;
|
|
pgno_t pgno;
|
|
|
|
bzero(data, sizeof(*data));
|
|
max = db->md_env->me_head.mh_psize - PAGEHDRSZ;
|
|
|
|
if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
|
|
data->mv_size = leaf->mn_dsize;
|
|
data->mv_data = NODEDATA(leaf);
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
/* Read overflow data.
|
|
*/
|
|
data->mv_size = leaf->mn_dsize;
|
|
bcopy(NODEDATA(leaf), &pgno, sizeof(pgno));
|
|
if ((omp = mdbenv_get_page(db->md_env, pgno)) == NULL) {
|
|
DPRINTF("read overflow page %lu failed", pgno);
|
|
return MDB_FAIL;
|
|
}
|
|
data->mv_data = omp;
|
|
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
int
|
|
mdb_get(MDB_db *db, MDB_txn *txn,
|
|
MDB_val *key, MDB_val *data)
|
|
{
|
|
int rc, exact;
|
|
MDB_node *leaf;
|
|
MDB_pageparent mpp;
|
|
|
|
assert(key);
|
|
assert(data);
|
|
DPRINTF("===> get key [%.*s]", (int)key->mv_size, (char *)key->mv_data);
|
|
|
|
if (db == NULL)
|
|
return EINVAL;
|
|
|
|
if (txn != NULL && db->md_env != txn->mt_env) {
|
|
return EINVAL;
|
|
}
|
|
|
|
if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
|
|
return EINVAL;
|
|
}
|
|
|
|
if ((rc = mdb_search_page(db, txn, key, NULL, 0, &mpp)) != MDB_SUCCESS)
|
|
return rc;
|
|
|
|
leaf = mdb_search_node(db, mpp.mp_page, key, &exact, NULL);
|
|
if (leaf && exact)
|
|
rc = mdb_read_data(db, mpp.mp_page, leaf, data);
|
|
else {
|
|
rc = ENOENT;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
static int
|
|
mdb_sibling(MDB_cursor *cursor, int move_right)
|
|
{
|
|
int rc;
|
|
MDB_node *indx;
|
|
MDB_ppage *parent, *top;
|
|
MDB_page *mp;
|
|
|
|
top = CURSOR_TOP(cursor);
|
|
if ((parent = SLIST_NEXT(top, mp_entry)) == NULL) {
|
|
return ENOENT; /* root has no siblings */
|
|
}
|
|
|
|
DPRINTF("parent page is page %lu, index %u",
|
|
parent->mp_page->mp_pgno, parent->mp_ki);
|
|
|
|
cursor_pop_page(cursor);
|
|
if (move_right ? (parent->mp_ki + 1 >= NUMKEYS(parent->mp_page))
|
|
: (parent->mp_ki == 0)) {
|
|
DPRINTF("no more keys left, moving to %s sibling",
|
|
move_right ? "right" : "left");
|
|
if ((rc = mdb_sibling(cursor, move_right)) != MDB_SUCCESS)
|
|
return rc;
|
|
parent = CURSOR_TOP(cursor);
|
|
} else {
|
|
if (move_right)
|
|
parent->mp_ki++;
|
|
else
|
|
parent->mp_ki--;
|
|
DPRINTF("just moving to %s index key %u",
|
|
move_right ? "right" : "left", parent->mp_ki);
|
|
}
|
|
assert(IS_BRANCH(parent->mp_page));
|
|
|
|
indx = NODEPTR(parent->mp_page, parent->mp_ki);
|
|
if ((mp = mdbenv_get_page(cursor->mc_db->md_env, indx->mn_pgno)) == NULL)
|
|
return MDB_FAIL;
|
|
#if 0
|
|
mp->parent = parent->mp_page;
|
|
mp->parent_index = parent->mp_ki;
|
|
#endif
|
|
|
|
cursor_push_page(cursor, mp);
|
|
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
static int
|
|
mdb_set_key(MDB_db *bt, MDB_page *mp, MDB_node *node,
|
|
MDB_val *key)
|
|
{
|
|
if (key == NULL)
|
|
return 0;
|
|
|
|
key->mv_size = node->mn_ksize;
|
|
key->mv_data = NODEKEY(node);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
mdb_cursor_next(MDB_cursor *cursor, MDB_val *key, MDB_val *data)
|
|
{
|
|
MDB_ppage *top;
|
|
MDB_page *mp;
|
|
MDB_node *leaf;
|
|
|
|
if (cursor->mc_eof) {
|
|
return ENOENT;
|
|
}
|
|
|
|
assert(cursor->mc_initialized);
|
|
|
|
top = CURSOR_TOP(cursor);
|
|
mp = top->mp_page;
|
|
|
|
DPRINTF("cursor_next: top page is %lu in cursor %p", mp->mp_pgno, cursor);
|
|
|
|
if (top->mp_ki + 1 >= NUMKEYS(mp)) {
|
|
DPRINTF("=====> move to next sibling page");
|
|
if (mdb_sibling(cursor, 1) != MDB_SUCCESS) {
|
|
cursor->mc_eof = 1;
|
|
return ENOENT;
|
|
}
|
|
top = CURSOR_TOP(cursor);
|
|
mp = top->mp_page;
|
|
DPRINTF("next page is %lu, key index %u", mp->mp_pgno, top->mp_ki);
|
|
} else
|
|
top->mp_ki++;
|
|
|
|
DPRINTF("==> cursor points to page %lu with %lu keys, key index %u",
|
|
mp->mp_pgno, NUMKEYS(mp), top->mp_ki);
|
|
|
|
assert(IS_LEAF(mp));
|
|
leaf = NODEPTR(mp, top->mp_ki);
|
|
|
|
if (data && mdb_read_data(cursor->mc_db, mp, leaf, data) != MDB_SUCCESS)
|
|
return MDB_FAIL;
|
|
|
|
return mdb_set_key(cursor->mc_db, mp, leaf, key);
|
|
}
|
|
|
|
static int
|
|
mdb_cursor_set(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
|
|
int *exactp)
|
|
{
|
|
int rc;
|
|
MDB_node *leaf;
|
|
MDB_ppage *top;
|
|
MDB_pageparent mpp;
|
|
|
|
assert(cursor);
|
|
assert(key);
|
|
assert(key->mv_size > 0);
|
|
|
|
rc = mdb_search_page(cursor->mc_db, cursor->mc_txn, key, cursor, 0, &mpp);
|
|
if (rc != MDB_SUCCESS)
|
|
return rc;
|
|
assert(IS_LEAF(mpp.mp_page));
|
|
|
|
top = CURSOR_TOP(cursor);
|
|
leaf = mdb_search_node(cursor->mc_db, mpp.mp_page, key, exactp, &top->mp_ki);
|
|
if (exactp != NULL && !*exactp) {
|
|
/* MDB_CURSOR_EXACT specified and not an exact match. */
|
|
return ENOENT;
|
|
}
|
|
|
|
if (leaf == NULL) {
|
|
DPRINTF("===> inexact leaf not found, goto sibling");
|
|
if ((rc = mdb_sibling(cursor, 1)) != MDB_SUCCESS)
|
|
return rc; /* no entries matched */
|
|
top = CURSOR_TOP(cursor);
|
|
top->mp_ki = 0;
|
|
mpp.mp_page = top->mp_page;
|
|
assert(IS_LEAF(mpp.mp_page));
|
|
leaf = NODEPTR(mpp.mp_page, 0);
|
|
}
|
|
|
|
cursor->mc_initialized = 1;
|
|
cursor->mc_eof = 0;
|
|
|
|
if (data && (rc = mdb_read_data(cursor->mc_db, mpp.mp_page, leaf, data)) != MDB_SUCCESS)
|
|
return rc;
|
|
|
|
rc = mdb_set_key(cursor->mc_db, mpp.mp_page, leaf, key);
|
|
if (rc == MDB_SUCCESS) {
|
|
DPRINTF("==> cursor placed on key %.*s",
|
|
(int)key->mv_size, (char *)key->mv_data);
|
|
;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
static int
|
|
mdb_cursor_first(MDB_cursor *cursor, MDB_val *key, MDB_val *data)
|
|
{
|
|
int rc;
|
|
MDB_pageparent mpp;
|
|
MDB_node *leaf;
|
|
|
|
rc = mdb_search_page(cursor->mc_db, cursor->mc_txn, NULL, cursor, 0, &mpp);
|
|
if (rc != MDB_SUCCESS)
|
|
return rc;
|
|
assert(IS_LEAF(mpp.mp_page));
|
|
|
|
leaf = NODEPTR(mpp.mp_page, 0);
|
|
cursor->mc_initialized = 1;
|
|
cursor->mc_eof = 0;
|
|
|
|
if (data && (rc = mdb_read_data(cursor->mc_db, mpp.mp_page, leaf, data)) != MDB_SUCCESS)
|
|
return rc;
|
|
|
|
return mdb_set_key(cursor->mc_db, mpp.mp_page, leaf, key);
|
|
}
|
|
|
|
int
|
|
mdb_cursor_get(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
|
|
MDB_cursor_op op)
|
|
{
|
|
int rc;
|
|
int exact = 0;
|
|
|
|
assert(cursor);
|
|
|
|
switch (op) {
|
|
case MDB_CURSOR:
|
|
case MDB_CURSOR_EXACT:
|
|
while (CURSOR_TOP(cursor) != NULL)
|
|
cursor_pop_page(cursor);
|
|
if (key == NULL || key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
|
|
rc = EINVAL;
|
|
} else if (op == MDB_CURSOR_EXACT)
|
|
rc = mdb_cursor_set(cursor, key, data, &exact);
|
|
else
|
|
rc = mdb_cursor_set(cursor, key, data, NULL);
|
|
break;
|
|
case MDB_NEXT:
|
|
if (!cursor->mc_initialized)
|
|
rc = mdb_cursor_first(cursor, key, data);
|
|
else
|
|
rc = mdb_cursor_next(cursor, key, data);
|
|
break;
|
|
case MDB_FIRST:
|
|
while (CURSOR_TOP(cursor) != NULL)
|
|
cursor_pop_page(cursor);
|
|
rc = mdb_cursor_first(cursor, key, data);
|
|
break;
|
|
default:
|
|
DPRINTF("unhandled/unimplemented cursor operation %u", op);
|
|
rc = EINVAL;
|
|
break;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/* Allocate a page and initialize it
|
|
*/
|
|
static MDB_dpage *
|
|
mdbenv_new_page(MDB_env *env, uint32_t flags, int num)
|
|
{
|
|
MDB_dpage *dp;
|
|
|
|
assert(env != NULL);
|
|
assert(env->me_txn != NULL);
|
|
|
|
DPRINTF("allocating new mpage %lu, page size %u",
|
|
env->me_txn->mt_next_pgno, env->me_head.mh_psize);
|
|
if ((dp = mdb_newpage(env->me_txn, NULL, 0, num)) == NULL)
|
|
return NULL;
|
|
dp->p.mp_flags = flags | P_DIRTY;
|
|
dp->p.mp_lower = PAGEHDRSZ;
|
|
dp->p.mp_upper = env->me_head.mh_psize;
|
|
|
|
if (IS_BRANCH(&dp->p))
|
|
env->me_meta.mm_stat.ms_branch_pages++;
|
|
else if (IS_LEAF(&dp->p))
|
|
env->me_meta.mm_stat.ms_leaf_pages++;
|
|
else if (IS_OVERFLOW(&dp->p)) {
|
|
env->me_meta.mm_stat.ms_overflow_pages += num;
|
|
dp->p.mp_pages = num;
|
|
}
|
|
|
|
return dp;
|
|
}
|
|
|
|
static size_t
|
|
mdb_leaf_size(MDB_db *db, MDB_val *key, MDB_val *data)
|
|
{
|
|
size_t sz;
|
|
|
|
sz = LEAFSIZE(key, data);
|
|
if (data->mv_size >= db->md_env->me_head.mh_psize / MDB_MINKEYS) {
|
|
/* put on overflow page */
|
|
sz -= data->mv_size - sizeof(pgno_t);
|
|
}
|
|
|
|
return sz + sizeof(indx_t);
|
|
}
|
|
|
|
static size_t
|
|
mdb_branch_size(MDB_db *db, MDB_val *key)
|
|
{
|
|
size_t sz;
|
|
|
|
sz = INDXSIZE(key);
|
|
if (sz >= db->md_env->me_head.mh_psize / MDB_MINKEYS) {
|
|
/* put on overflow page */
|
|
/* not implemented */
|
|
/* sz -= key->size - sizeof(pgno_t); */
|
|
}
|
|
|
|
return sz + sizeof(indx_t);
|
|
}
|
|
|
|
static int
|
|
mdb_add_node(MDB_db *db, MDB_page *mp, indx_t indx,
|
|
MDB_val *key, MDB_val *data, pgno_t pgno, uint8_t flags)
|
|
{
|
|
unsigned int i;
|
|
size_t node_size = NODESIZE;
|
|
indx_t ofs;
|
|
MDB_node *node;
|
|
MDB_dpage *ofp = NULL; /* overflow page */
|
|
|
|
assert(mp->mp_upper >= mp->mp_lower);
|
|
|
|
DPRINTF("add node [%.*s] to %s page %lu at index %i, key size %zu",
|
|
key ? (int)key->mv_size : 0, key ? (char *)key->mv_data : NULL,
|
|
IS_LEAF(mp) ? "leaf" : "branch",
|
|
mp->mp_pgno, indx, key ? key->mv_size : 0);
|
|
|
|
if (key != NULL)
|
|
node_size += key->mv_size;
|
|
|
|
if (IS_LEAF(mp)) {
|
|
assert(data);
|
|
node_size += data->mv_size;
|
|
if (F_ISSET(flags, F_BIGDATA)) {
|
|
/* Data already on overflow page. */
|
|
node_size -= data->mv_size - sizeof(pgno_t);
|
|
} else if (data->mv_size >= db->md_env->me_head.mh_psize / MDB_MINKEYS) {
|
|
int ovpages = PAGEHDRSZ + data->mv_size + db->md_env->me_head.mh_psize - 1;
|
|
ovpages /= db->md_env->me_head.mh_psize;
|
|
/* Put data on overflow page. */
|
|
DPRINTF("data size is %zu, put on overflow page",
|
|
data->mv_size);
|
|
node_size -= data->mv_size - sizeof(pgno_t);
|
|
if ((ofp = mdbenv_new_page(db->md_env, P_OVERFLOW, ovpages)) == NULL)
|
|
return MDB_FAIL;
|
|
DPRINTF("allocated overflow page %lu", ofp->p.mp_pgno);
|
|
flags |= F_BIGDATA;
|
|
}
|
|
}
|
|
|
|
if (node_size + sizeof(indx_t) > SIZELEFT(mp)) {
|
|
DPRINTF("not enough room in page %lu, got %lu ptrs",
|
|
mp->mp_pgno, NUMKEYS(mp));
|
|
DPRINTF("upper - lower = %u - %u = %u", mp->mp_upper, mp->mp_lower,
|
|
mp->mp_upper - mp->mp_lower);
|
|
DPRINTF("node size = %zu", node_size);
|
|
return ENOSPC;
|
|
}
|
|
|
|
/* Move higher pointers up one slot. */
|
|
for (i = NUMKEYS(mp); i > indx; i--)
|
|
mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
|
|
|
|
/* Adjust free space offsets. */
|
|
ofs = mp->mp_upper - node_size;
|
|
assert(ofs >= mp->mp_lower + sizeof(indx_t));
|
|
mp->mp_ptrs[indx] = ofs;
|
|
mp->mp_upper = ofs;
|
|
mp->mp_lower += sizeof(indx_t);
|
|
|
|
/* Write the node data. */
|
|
node = NODEPTR(mp, indx);
|
|
node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
|
|
node->mn_flags = flags;
|
|
if (IS_LEAF(mp))
|
|
node->mn_dsize = data->mv_size;
|
|
else
|
|
node->mn_pgno = pgno;
|
|
|
|
if (key)
|
|
bcopy(key->mv_data, NODEKEY(node), key->mv_size);
|
|
|
|
if (IS_LEAF(mp)) {
|
|
assert(key);
|
|
if (ofp == NULL) {
|
|
if (F_ISSET(flags, F_BIGDATA))
|
|
bcopy(data->mv_data, node->mn_data + key->mv_size,
|
|
sizeof(pgno_t));
|
|
else
|
|
bcopy(data->mv_data, node->mn_data + key->mv_size,
|
|
data->mv_size);
|
|
} else {
|
|
bcopy(&ofp->p.mp_pgno, node->mn_data + key->mv_size,
|
|
sizeof(pgno_t));
|
|
bcopy(data->mv_data, METADATA(&ofp->p), data->mv_size);
|
|
}
|
|
}
|
|
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
static void
|
|
mdb_del_node(MDB_db *db, MDB_page *mp, indx_t indx)
|
|
{
|
|
unsigned int sz;
|
|
indx_t i, j, numkeys, ptr;
|
|
MDB_node *node;
|
|
char *base;
|
|
|
|
DPRINTF("delete node %u on %s page %lu", indx,
|
|
IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno);
|
|
assert(indx < NUMKEYS(mp));
|
|
|
|
node = NODEPTR(mp, indx);
|
|
sz = NODESIZE + node->mn_ksize;
|
|
if (IS_LEAF(mp)) {
|
|
if (F_ISSET(node->mn_flags, F_BIGDATA))
|
|
sz += sizeof(pgno_t);
|
|
else
|
|
sz += NODEDSZ(node);
|
|
}
|
|
|
|
ptr = mp->mp_ptrs[indx];
|
|
numkeys = NUMKEYS(mp);
|
|
for (i = j = 0; i < numkeys; i++) {
|
|
if (i != indx) {
|
|
mp->mp_ptrs[j] = mp->mp_ptrs[i];
|
|
if (mp->mp_ptrs[i] < ptr)
|
|
mp->mp_ptrs[j] += sz;
|
|
j++;
|
|
}
|
|
}
|
|
|
|
base = (char *)mp + mp->mp_upper;
|
|
bcopy(base, base + sz, ptr - mp->mp_upper);
|
|
|
|
mp->mp_lower -= sizeof(indx_t);
|
|
mp->mp_upper += sz;
|
|
}
|
|
|
|
int
|
|
mdb_cursor_open(MDB_db *db, MDB_txn *txn, MDB_cursor **ret)
|
|
{
|
|
MDB_cursor *cursor;
|
|
|
|
if (db == NULL || ret == NULL)
|
|
return EINVAL;
|
|
|
|
if (txn != NULL && db->md_env != txn->mt_env) {
|
|
return EINVAL;
|
|
}
|
|
|
|
if ((cursor = calloc(1, sizeof(*cursor))) != NULL) {
|
|
SLIST_INIT(&cursor->mc_stack);
|
|
cursor->mc_db = db;
|
|
cursor->mc_txn = txn;
|
|
}
|
|
|
|
*ret = cursor;
|
|
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
void
|
|
mdb_cursor_close(MDB_cursor *cursor)
|
|
{
|
|
if (cursor != NULL) {
|
|
while (!CURSOR_EMPTY(cursor))
|
|
cursor_pop_page(cursor);
|
|
|
|
/* btree_close(cursor->bt); */
|
|
free(cursor);
|
|
}
|
|
}
|
|
|
|
static int
|
|
mdb_update_key(MDB_db *db, MDB_page *mp, indx_t indx,
|
|
MDB_val *key)
|
|
{
|
|
indx_t ptr, i, numkeys;
|
|
int delta;
|
|
size_t len;
|
|
MDB_node *node;
|
|
char *base;
|
|
|
|
node = NODEPTR(mp, indx);
|
|
ptr = mp->mp_ptrs[indx];
|
|
DPRINTF("update key %u (ofs %u) [%.*s] to [%.*s] on page %lu",
|
|
indx, ptr,
|
|
(int)node->mn_ksize, (char *)NODEKEY(node),
|
|
(int)key->mv_size, (char *)key->mv_data,
|
|
mp->mp_pgno);
|
|
|
|
delta = key->mv_size - node->mn_ksize;
|
|
if (delta) {
|
|
if (delta > 0 && SIZELEFT(mp) < delta) {
|
|
DPRINTF("OUCH! Not enough room, delta = %d", delta);
|
|
return ENOSPC;
|
|
}
|
|
|
|
numkeys = NUMKEYS(mp);
|
|
for (i = 0; i < numkeys; i++) {
|
|
if (mp->mp_ptrs[i] <= ptr)
|
|
mp->mp_ptrs[i] -= delta;
|
|
}
|
|
|
|
base = (char *)mp + mp->mp_upper;
|
|
len = ptr - mp->mp_upper + NODESIZE;
|
|
bcopy(base, base - delta, len);
|
|
mp->mp_upper -= delta;
|
|
|
|
node = NODEPTR(mp, indx);
|
|
node->mn_ksize = key->mv_size;
|
|
}
|
|
|
|
bcopy(key->mv_data, NODEKEY(node), key->mv_size);
|
|
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
/* Move a node from src to dst.
|
|
*/
|
|
static int
|
|
mdb_move_node(MDB_db *bt, MDB_pageparent *src, indx_t srcindx,
|
|
MDB_pageparent *dst, indx_t dstindx)
|
|
{
|
|
int rc;
|
|
MDB_node *srcnode;
|
|
MDB_val key, data;
|
|
|
|
srcnode = NODEPTR(src->mp_page, srcindx);
|
|
DPRINTF("moving %s node %u [%.*s] on page %lu to node %u on page %lu",
|
|
IS_LEAF(src->mp_page) ? "leaf" : "branch",
|
|
srcindx,
|
|
(int)srcnode->mn_ksize, (char *)NODEKEY(srcnode),
|
|
src->mp_page->mp_pgno,
|
|
dstindx, dst->mp_page->mp_pgno);
|
|
|
|
/* Mark src and dst as dirty. */
|
|
if ((rc = mdb_touch(bt->md_env->me_txn, src)) ||
|
|
(rc = mdb_touch(bt->md_env->me_txn, dst)))
|
|
return rc;;
|
|
|
|
/* Add the node to the destination page.
|
|
*/
|
|
key.mv_size = srcnode->mn_ksize;
|
|
key.mv_data = NODEKEY(srcnode);
|
|
data.mv_size = NODEDSZ(srcnode);
|
|
data.mv_data = NODEDATA(srcnode);
|
|
rc = mdb_add_node(bt, dst->mp_page, dstindx, &key, &data, NODEPGNO(srcnode),
|
|
srcnode->mn_flags);
|
|
if (rc != MDB_SUCCESS)
|
|
return rc;
|
|
|
|
/* Delete the node from the source page.
|
|
*/
|
|
mdb_del_node(bt, src->mp_page, srcindx);
|
|
|
|
/* Update the parent separators.
|
|
*/
|
|
if (srcindx == 0 && src->mp_pi != 0) {
|
|
DPRINTF("update separator for source page %lu to [%.*s]",
|
|
src->mp_page->mp_pgno, (int)key.mv_size, (char *)key.mv_data);
|
|
if ((rc = mdb_update_key(bt, src->mp_parent, src->mp_pi,
|
|
&key)) != MDB_SUCCESS)
|
|
return rc;
|
|
}
|
|
|
|
if (srcindx == 0 && IS_BRANCH(src->mp_page)) {
|
|
MDB_val nullkey;
|
|
nullkey.mv_size = 0;
|
|
assert(mdb_update_key(bt, src->mp_page, 0, &nullkey) == MDB_SUCCESS);
|
|
}
|
|
|
|
if (dstindx == 0 && dst->mp_pi != 0) {
|
|
DPRINTF("update separator for destination page %lu to [%.*s]",
|
|
dst->mp_page->mp_pgno, (int)key.mv_size, (char *)key.mv_data);
|
|
if ((rc = mdb_update_key(bt, dst->mp_parent, dst->mp_pi,
|
|
&key)) != MDB_SUCCESS)
|
|
return rc;
|
|
}
|
|
|
|
if (dstindx == 0 && IS_BRANCH(dst->mp_page)) {
|
|
MDB_val nullkey;
|
|
nullkey.mv_size = 0;
|
|
assert(mdb_update_key(bt, dst->mp_page, 0, &nullkey) == MDB_SUCCESS);
|
|
}
|
|
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
static int
|
|
mdb_merge(MDB_db *bt, MDB_pageparent *src, MDB_pageparent *dst)
|
|
{
|
|
int rc;
|
|
indx_t i;
|
|
MDB_node *srcnode;
|
|
MDB_val key, data;
|
|
MDB_pageparent mpp;
|
|
MDB_dhead *dh;
|
|
|
|
DPRINTF("merging page %lu and %lu", src->mp_page->mp_pgno, dst->mp_page->mp_pgno);
|
|
|
|
assert(src->mp_parent); /* can't merge root page */
|
|
assert(dst->mp_parent);
|
|
assert(bt->md_env->me_txn != NULL);
|
|
|
|
/* Mark src and dst as dirty. */
|
|
if ((rc = mdb_touch(bt->md_env->me_txn, src)) ||
|
|
(rc = mdb_touch(bt->md_env->me_txn, dst)))
|
|
return rc;
|
|
|
|
/* Move all nodes from src to dst.
|
|
*/
|
|
for (i = 0; i < NUMKEYS(src->mp_page); i++) {
|
|
srcnode = NODEPTR(src->mp_page, i);
|
|
|
|
key.mv_size = srcnode->mn_ksize;
|
|
key.mv_data = NODEKEY(srcnode);
|
|
data.mv_size = NODEDSZ(srcnode);
|
|
data.mv_data = NODEDATA(srcnode);
|
|
rc = mdb_add_node(bt, dst->mp_page, NUMKEYS(dst->mp_page), &key,
|
|
&data, NODEPGNO(srcnode), srcnode->mn_flags);
|
|
if (rc != MDB_SUCCESS)
|
|
return rc;
|
|
}
|
|
|
|
DPRINTF("dst page %lu now has %lu keys (%.1f%% filled)",
|
|
dst->mp_page->mp_pgno, NUMKEYS(dst->mp_page), (float)PAGEFILL(bt->md_env, dst->mp_page) / 10);
|
|
|
|
/* Unlink the src page from parent.
|
|
*/
|
|
mdb_del_node(bt, src->mp_parent, src->mp_pi);
|
|
if (src->mp_pi == 0) {
|
|
key.mv_size = 0;
|
|
if ((rc = mdb_update_key(bt, src->mp_parent, 0, &key)) != MDB_SUCCESS)
|
|
return rc;
|
|
}
|
|
|
|
if (IS_LEAF(src->mp_page))
|
|
bt->md_env->me_meta.mm_stat.ms_leaf_pages--;
|
|
else
|
|
bt->md_env->me_meta.mm_stat.ms_branch_pages--;
|
|
|
|
mpp.mp_page = src->mp_parent;
|
|
dh = (MDB_dhead *)src->mp_parent;
|
|
dh--;
|
|
mpp.mp_parent = dh->md_parent;
|
|
mpp.mp_pi = dh->md_pi;
|
|
|
|
return mdb_rebalance(bt, &mpp);
|
|
}
|
|
|
|
#define FILL_THRESHOLD 250
|
|
|
|
static int
|
|
mdb_rebalance(MDB_db *db, MDB_pageparent *mpp)
|
|
{
|
|
MDB_node *node;
|
|
MDB_page *root;
|
|
MDB_pageparent npp;
|
|
indx_t si = 0, di = 0;
|
|
|
|
assert(db != NULL);
|
|
assert(db->md_env->me_txn != NULL);
|
|
assert(mpp != NULL);
|
|
|
|
DPRINTF("rebalancing %s page %lu (has %lu keys, %.1f%% full)",
|
|
IS_LEAF(mpp->mp_page) ? "leaf" : "branch",
|
|
mpp->mp_page->mp_pgno, NUMKEYS(mpp->mp_page), (float)PAGEFILL(db->md_env, mpp->mp_page) / 10);
|
|
|
|
if (PAGEFILL(db->md_env, mpp->mp_page) >= FILL_THRESHOLD) {
|
|
DPRINTF("no need to rebalance page %lu, above fill threshold",
|
|
mpp->mp_page->mp_pgno);
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
if (mpp->mp_parent == NULL) {
|
|
if (NUMKEYS(mpp->mp_page) == 0) {
|
|
DPRINTF("tree is completely empty");
|
|
db->md_env->me_txn->mt_root = P_INVALID;
|
|
db->md_env->me_meta.mm_stat.ms_depth--;
|
|
db->md_env->me_meta.mm_stat.ms_leaf_pages--;
|
|
} else if (IS_BRANCH(mpp->mp_page) && NUMKEYS(mpp->mp_page) == 1) {
|
|
DPRINTF("collapsing root page!");
|
|
db->md_env->me_txn->mt_root = NODEPGNO(NODEPTR(mpp->mp_page, 0));
|
|
if ((root = mdbenv_get_page(db->md_env, db->md_env->me_txn->mt_root)) == NULL)
|
|
return MDB_FAIL;
|
|
db->md_env->me_meta.mm_stat.ms_depth--;
|
|
db->md_env->me_meta.mm_stat.ms_branch_pages--;
|
|
} else
|
|
DPRINTF("root page doesn't need rebalancing");
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
/* The parent (branch page) must have at least 2 pointers,
|
|
* otherwise the tree is invalid.
|
|
*/
|
|
assert(NUMKEYS(mpp->mp_parent) > 1);
|
|
|
|
/* Leaf page fill factor is below the threshold.
|
|
* Try to move keys from left or right neighbor, or
|
|
* merge with a neighbor page.
|
|
*/
|
|
|
|
/* Find neighbors.
|
|
*/
|
|
if (mpp->mp_pi == 0) {
|
|
/* We're the leftmost leaf in our parent.
|
|
*/
|
|
DPRINTF("reading right neighbor");
|
|
node = NODEPTR(mpp->mp_parent, mpp->mp_pi + 1);
|
|
if ((npp.mp_page = mdbenv_get_page(db->md_env, NODEPGNO(node))) == NULL)
|
|
return MDB_FAIL;
|
|
npp.mp_pi = mpp->mp_pi + 1;
|
|
si = 0;
|
|
di = NUMKEYS(mpp->mp_page);
|
|
} else {
|
|
/* There is at least one neighbor to the left.
|
|
*/
|
|
DPRINTF("reading left neighbor");
|
|
node = NODEPTR(mpp->mp_parent, mpp->mp_pi - 1);
|
|
if ((npp.mp_page = mdbenv_get_page(db->md_env, NODEPGNO(node))) == NULL)
|
|
return MDB_FAIL;
|
|
npp.mp_pi = mpp->mp_pi - 1;
|
|
si = NUMKEYS(npp.mp_page) - 1;
|
|
di = 0;
|
|
}
|
|
npp.mp_parent = mpp->mp_parent;
|
|
|
|
DPRINTF("found neighbor page %lu (%lu keys, %.1f%% full)",
|
|
npp.mp_page->mp_pgno, NUMKEYS(npp.mp_page), (float)PAGEFILL(db->md_env, npp.mp_page) / 10);
|
|
|
|
/* If the neighbor page is above threshold and has at least two
|
|
* keys, move one key from it.
|
|
*
|
|
* Otherwise we should try to merge them.
|
|
*/
|
|
if (PAGEFILL(db->md_env, npp.mp_page) >= FILL_THRESHOLD && NUMKEYS(npp.mp_page) >= 2)
|
|
return mdb_move_node(db, &npp, si, mpp, di);
|
|
else { /* FIXME: if (has_enough_room()) */
|
|
if (mpp->mp_pi == 0)
|
|
return mdb_merge(db, &npp, mpp);
|
|
else
|
|
return mdb_merge(db, mpp, &npp);
|
|
}
|
|
}
|
|
|
|
int
|
|
mdb_del(MDB_db *bt, MDB_txn *txn,
|
|
MDB_val *key, MDB_val *data)
|
|
{
|
|
int rc, exact;
|
|
unsigned int ki;
|
|
MDB_node *leaf;
|
|
MDB_pageparent mpp;
|
|
|
|
DPRINTF("========> delete key %.*s", (int)key->mv_size, (char *)key->mv_data);
|
|
|
|
assert(key != NULL);
|
|
|
|
if (bt == NULL || txn == NULL)
|
|
return EINVAL;
|
|
|
|
if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
|
|
return EINVAL;
|
|
}
|
|
|
|
if (bt->md_env->me_txn != txn) {
|
|
return EINVAL;
|
|
}
|
|
|
|
if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
|
|
return EINVAL;
|
|
}
|
|
|
|
if ((rc = mdb_search_page(bt, txn, key, NULL, 1, &mpp)) != MDB_SUCCESS)
|
|
return rc;
|
|
|
|
leaf = mdb_search_node(bt, mpp.mp_page, key, &exact, &ki);
|
|
if (leaf == NULL || !exact) {
|
|
return ENOENT;
|
|
}
|
|
|
|
if (data && (rc = mdb_read_data(bt, NULL, leaf, data)) != MDB_SUCCESS)
|
|
return rc;
|
|
|
|
mdb_del_node(bt, mpp.mp_page, ki);
|
|
bt->md_env->me_meta.mm_stat.ms_entries--;
|
|
rc = mdb_rebalance(bt, &mpp);
|
|
if (rc != MDB_SUCCESS)
|
|
txn->mt_flags |= MDB_TXN_ERROR;
|
|
|
|
return rc;
|
|
}
|
|
|
|
/* Split page <*mpp>, and insert <key,(data|newpgno)> in either left or
|
|
* right sibling, at index <*newindxp> (as if unsplit). Updates *mpp and
|
|
* *newindxp with the actual values after split, ie if *mpp and *newindxp
|
|
* refer to a node in the new right sibling page.
|
|
*/
|
|
static int
|
|
mdb_split(MDB_db *bt, MDB_page **mpp, unsigned int *newindxp,
|
|
MDB_val *newkey, MDB_val *newdata, pgno_t newpgno)
|
|
{
|
|
uint8_t flags;
|
|
int rc = MDB_SUCCESS, ins_new = 0;
|
|
indx_t newindx;
|
|
pgno_t pgno = 0;
|
|
unsigned int i, j, split_indx;
|
|
MDB_node *node;
|
|
MDB_page *pright, *p;
|
|
MDB_val sepkey, rkey, rdata;
|
|
MDB_page *copy;
|
|
MDB_dpage *mdp, *rdp, *pdp;
|
|
MDB_dhead *dh;
|
|
|
|
assert(bt != NULL);
|
|
assert(bt->md_env != NULL);
|
|
|
|
dh = ((MDB_dhead *)*mpp) - 1;
|
|
mdp = (MDB_dpage *)dh;
|
|
newindx = *newindxp;
|
|
|
|
DPRINTF("-----> splitting %s page %lu and adding [%.*s] at index %i",
|
|
IS_LEAF(&mdp->p) ? "leaf" : "branch", mdp->p.mp_pgno,
|
|
(int)newkey->mv_size, (char *)newkey->mv_data, *newindxp);
|
|
|
|
if (mdp->h.md_parent == NULL) {
|
|
if ((pdp = mdbenv_new_page(bt->md_env, P_BRANCH, 1)) == NULL)
|
|
return MDB_FAIL;
|
|
mdp->h.md_pi = 0;
|
|
mdp->h.md_parent = &pdp->p;
|
|
bt->md_env->me_txn->mt_root = pdp->p.mp_pgno;
|
|
DPRINTF("root split! new root = %lu", pdp->p.mp_pgno);
|
|
bt->md_env->me_meta.mm_stat.ms_depth++;
|
|
|
|
/* Add left (implicit) pointer. */
|
|
if (mdb_add_node(bt, &pdp->p, 0, NULL, NULL,
|
|
mdp->p.mp_pgno, 0) != MDB_SUCCESS)
|
|
return MDB_FAIL;
|
|
} else {
|
|
DPRINTF("parent branch page is %lu", mdp->h.md_parent->mp_pgno);
|
|
}
|
|
|
|
/* Create a right sibling. */
|
|
if ((rdp = mdbenv_new_page(bt->md_env, mdp->p.mp_flags, 1)) == NULL)
|
|
return MDB_FAIL;
|
|
rdp->h.md_parent = mdp->h.md_parent;
|
|
rdp->h.md_pi = mdp->h.md_pi + 1;
|
|
DPRINTF("new right sibling: page %lu", rdp->p.mp_pgno);
|
|
|
|
/* Move half of the keys to the right sibling. */
|
|
if ((copy = malloc(bt->md_env->me_head.mh_psize)) == NULL)
|
|
return MDB_FAIL;
|
|
bcopy(&mdp->p, copy, bt->md_env->me_head.mh_psize);
|
|
bzero(&mdp->p.mp_ptrs, bt->md_env->me_head.mh_psize - PAGEHDRSZ);
|
|
mdp->p.mp_lower = PAGEHDRSZ;
|
|
mdp->p.mp_upper = bt->md_env->me_head.mh_psize;
|
|
|
|
split_indx = NUMKEYS(copy) / 2 + 1;
|
|
|
|
/* First find the separating key between the split pages.
|
|
*/
|
|
bzero(&sepkey, sizeof(sepkey));
|
|
if (newindx == split_indx) {
|
|
sepkey.mv_size = newkey->mv_size;
|
|
sepkey.mv_data = newkey->mv_data;
|
|
} else {
|
|
node = NODEPTR(copy, split_indx);
|
|
sepkey.mv_size = node->mn_ksize;
|
|
sepkey.mv_data = NODEKEY(node);
|
|
}
|
|
|
|
DPRINTF("separator is [%.*s]", (int)sepkey.mv_size, (char *)sepkey.mv_data);
|
|
|
|
/* Copy separator key to the parent.
|
|
*/
|
|
if (SIZELEFT(rdp->h.md_parent) < mdb_branch_size(bt, &sepkey)) {
|
|
rc = mdb_split(bt, &rdp->h.md_parent, &rdp->h.md_pi,
|
|
&sepkey, NULL, rdp->p.mp_pgno);
|
|
|
|
/* Right page might now have changed parent.
|
|
* Check if left page also changed parent.
|
|
*/
|
|
if (rdp->h.md_parent != mdp->h.md_parent &&
|
|
mdp->h.md_pi >= NUMKEYS(mdp->h.md_parent)) {
|
|
mdp->h.md_parent = rdp->h.md_parent;
|
|
mdp->h.md_pi = rdp->h.md_pi - 1;
|
|
}
|
|
} else {
|
|
rc = mdb_add_node(bt, rdp->h.md_parent, rdp->h.md_pi,
|
|
&sepkey, NULL, rdp->p.mp_pgno, 0);
|
|
}
|
|
if (rc != MDB_SUCCESS) {
|
|
free(copy);
|
|
return MDB_FAIL;
|
|
}
|
|
|
|
for (i = j = 0; i <= NUMKEYS(copy); j++) {
|
|
if (i < split_indx) {
|
|
/* Re-insert in left sibling. */
|
|
pdp = mdp;
|
|
} else {
|
|
/* Insert in right sibling. */
|
|
if (i == split_indx)
|
|
/* Reset insert index for right sibling. */
|
|
j = (i == newindx && ins_new);
|
|
pdp = rdp;
|
|
}
|
|
|
|
if (i == newindx && !ins_new) {
|
|
/* Insert the original entry that caused the split. */
|
|
rkey.mv_data = newkey->mv_data;
|
|
rkey.mv_size = newkey->mv_size;
|
|
if (IS_LEAF(&mdp->p)) {
|
|
rdata.mv_data = newdata->mv_data;
|
|
rdata.mv_size = newdata->mv_size;
|
|
} else
|
|
pgno = newpgno;
|
|
flags = 0;
|
|
|
|
ins_new = 1;
|
|
|
|
/* Update page and index for the new key. */
|
|
*newindxp = j;
|
|
*mpp = &pdp->p;
|
|
} else if (i == NUMKEYS(copy)) {
|
|
break;
|
|
} else {
|
|
node = NODEPTR(copy, i);
|
|
rkey.mv_data = NODEKEY(node);
|
|
rkey.mv_size = node->mn_ksize;
|
|
if (IS_LEAF(&mdp->p)) {
|
|
rdata.mv_data = NODEDATA(node);
|
|
rdata.mv_size = node->mn_dsize;
|
|
} else
|
|
pgno = node->mn_pgno;
|
|
flags = node->mn_flags;
|
|
|
|
i++;
|
|
}
|
|
|
|
if (!IS_LEAF(&mdp->p) && j == 0) {
|
|
/* First branch index doesn't need key data. */
|
|
rkey.mv_size = 0;
|
|
}
|
|
|
|
rc = mdb_add_node(bt, &pdp->p, j, &rkey, &rdata, pgno,flags);
|
|
}
|
|
|
|
free(copy);
|
|
return rc;
|
|
}
|
|
|
|
int
|
|
mdb_put(MDB_db *bt, MDB_txn *txn,
|
|
MDB_val *key, MDB_val *data, unsigned int flags)
|
|
{
|
|
int rc = MDB_SUCCESS, exact;
|
|
unsigned int ki;
|
|
MDB_node *leaf;
|
|
MDB_pageparent mpp;
|
|
|
|
assert(key != NULL);
|
|
assert(data != NULL);
|
|
|
|
if (bt == NULL || txn == NULL)
|
|
return EINVAL;
|
|
|
|
if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
|
|
return EINVAL;
|
|
}
|
|
|
|
if (bt->md_env->me_txn != txn) {
|
|
return EINVAL;
|
|
}
|
|
|
|
if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
|
|
return EINVAL;
|
|
}
|
|
|
|
DPRINTF("==> put key %.*s, size %zu, data size %zu",
|
|
(int)key->mv_size, (char *)key->mv_data, key->mv_size, data->mv_size);
|
|
|
|
rc = mdb_search_page(bt, txn, key, NULL, 1, &mpp);
|
|
if (rc == MDB_SUCCESS) {
|
|
leaf = mdb_search_node(bt, mpp.mp_page, key, &exact, &ki);
|
|
if (leaf && exact) {
|
|
if (F_ISSET(flags, MDB_NOOVERWRITE)) {
|
|
DPRINTF("duplicate key %.*s",
|
|
(int)key->mv_size, (char *)key->mv_data);
|
|
return EEXIST;
|
|
}
|
|
mdb_del_node(bt, mpp.mp_page, ki);
|
|
}
|
|
if (leaf == NULL) { /* append if not found */
|
|
ki = NUMKEYS(mpp.mp_page);
|
|
DPRINTF("appending key at index %i", ki);
|
|
}
|
|
} else if (rc == ENOENT) {
|
|
MDB_dpage *dp;
|
|
/* new file, just write a root leaf page */
|
|
DPRINTF("allocating new root leaf page");
|
|
if ((dp = mdbenv_new_page(bt->md_env, P_LEAF, 1)) == NULL) {
|
|
return ENOMEM;
|
|
}
|
|
mpp.mp_page = &dp->p;
|
|
txn->mt_root = mpp.mp_page->mp_pgno;
|
|
bt->md_env->me_meta.mm_stat.ms_depth++;
|
|
ki = 0;
|
|
}
|
|
else
|
|
goto done;
|
|
|
|
assert(IS_LEAF(mpp.mp_page));
|
|
DPRINTF("there are %lu keys, should insert new key at index %i",
|
|
NUMKEYS(mpp.mp_page), ki);
|
|
|
|
if (SIZELEFT(mpp.mp_page) < mdb_leaf_size(bt, key, data)) {
|
|
rc = mdb_split(bt, &mpp.mp_page, &ki, key, data, P_INVALID);
|
|
} else {
|
|
/* There is room already in this leaf page. */
|
|
rc = mdb_add_node(bt, mpp.mp_page, ki, key, data, 0, 0);
|
|
}
|
|
|
|
if (rc != MDB_SUCCESS)
|
|
txn->mt_flags |= MDB_TXN_ERROR;
|
|
else
|
|
bt->md_env->me_meta.mm_stat.ms_entries++;
|
|
|
|
done:
|
|
return rc;
|
|
}
|
|
|
|
int
|
|
mdbenv_get_flags(MDB_env *env, unsigned int *arg)
|
|
{
|
|
if (!env || !arg)
|
|
return EINVAL;
|
|
|
|
*arg = env->me_flags;
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
int
|
|
mdbenv_get_path(MDB_env *env, const char **arg)
|
|
{
|
|
if (!env || !arg)
|
|
return EINVAL;
|
|
|
|
*arg = env->me_path;
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
int
|
|
mdbenv_stat(MDB_env *env, MDB_stat **arg)
|
|
{
|
|
if (env == NULL || arg == NULL)
|
|
return EINVAL;
|
|
|
|
*arg = &env->me_meta.mm_stat;
|
|
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
int mdb_open(MDB_env *env, MDB_txn *txn, const char *name, unsigned int flags, MDB_db **db)
|
|
{
|
|
if (!name) {
|
|
*db = (MDB_db *)&env->me_db;
|
|
return MDB_SUCCESS;
|
|
}
|
|
return EINVAL;
|
|
}
|
|
|
|
int mdb_stat(MDB_db *db, MDB_stat **arg)
|
|
{
|
|
if (db == NULL || arg == NULL)
|
|
return EINVAL;
|
|
|
|
*arg = &db->md_stat;
|
|
|
|
return MDB_SUCCESS;
|
|
}
|
|
|
|
void mdb_close(MDB_db *db)
|
|
{
|
|
}
|