netcdf-c/libdap4/d4util.h
Dennis Heimbigner 5fa2defc7e Improve fetch performance of DAP4
Prior to this PR, DAP4 always fetched the whole (constrained) dataset
This PR changes the query processing so
1. It reads data on a per-variable request (equivalent to calling nc_get_var()).
2. It tracks a response for every query.

Most of the changes reflect having to do per-variable requests.
In any case, doing all this significantly reduces the amount of data transmitted and hence speeds up DAP4 requests.
2023-10-08 19:59:28 -06:00

88 lines
2.4 KiB
C

/*********************************************************************
* Copyright 2018, UCAR/Unidata
* See netcdf/COPYRIGHT file for copying and redistribution conditions.
*********************************************************************/
#ifndef D4UTIL_H
#define D4UTIL_H 1
#ifdef HAVE_MEMMOVE
#define d4memmove(dst,src,n) memmove(dst,src,n)
#else
#define d4memmove(dst,src,n) localmemmove(dst,src,n)
#endif
/* This is intended to be big enough to work as
an offset/position/size for a file or a memory block.
*/
typedef unsigned long long d4size_t;
/* Define a (size, memory) pair */
typedef struct D4blob {d4size_t size; void* memory;} D4blob;
/* Empty blob constant */
#define NULLBLOB(blob) {blob.size = 0; blob.memory = NULL;}
#define OFFSET2BLOB(blob,offset) do{(blob).size = ((offset)->limit - (offset)->base); (blob).memory = (offset)->base; }while(0)
#define BLOB2OFFSET(offset,blob) do{\
(offset)->base = (blob).memory; \
(offset)->limit = ((char*)(blob).memory) + (blob).size; \
(offset)->offset = (offset)->base; \
} while(0)
/**************************************************/
/* signature: void swapinline16(void* ip) */
#define swapinline16(ip) \
{ \
char b[2]; \
char* src = (char*)(ip); \
b[0] = src[1]; \
b[1] = src[0]; \
memcpy(ip, b, 2); \
}
/* signature: void swapinline32(void* ip) */
#define swapinline32(ip) \
{ \
char b[4]; \
char* src = (char*)(ip); \
b[0] = src[3]; \
b[1] = src[2]; \
b[2] = src[1]; \
b[3] = src[0]; \
memcpy(ip, b, 4); \
}
/* signature: void swapinline64(void* ip) */
#define swapinline64(ip) \
{ \
char b[8]; \
char* src = (char*)(ip); \
b[0] = src[7]; \
b[1] = src[6]; \
b[2] = src[5]; \
b[3] = src[4]; \
b[4] = src[3]; \
b[5] = src[2]; \
b[6] = src[1]; \
b[7] = src[0]; \
memcpy(ip, b, 8); \
}
/***************************************************/
/* Define the NCD4node.data.flags */
#define HASNIL (0) /* no flags set */
#define HASSEQ (1) /* transitively contains sequence(s)*/
#define HASSTR (2) /* transitively contains strings */
#define HASOPFIX (4) /* transitively contains fixed size opaques */
#define HASOPVAR (8) /* transitively contains variable size opaques */
#define LEAFSEQ (16) /* mark leaf sequences */
#define HASANY (HASNIL|HASSEQ|HASSTR|HASOPTFIX|HASOPVAR)
/***************************************************/
extern int ncd4__testurl(const char* parth, char** basename);
#endif /*D4UTIL_H*/