netcdf-c/libsrc/ncio.c
Dennis Heimbigner 49737888ca Improve S3 Documentation and Support
## Improvements to S3 Documentation
* Create a new document *quickstart_paths.md* that give a summary of the legal path formats used by netcdf-c. This includes both file paths and URL paths.
* Modify *nczarr.md* to remove most of the S3 related text.
* Move the S3 text from *nczarr.md* to a new document *cloud.md*.
* Add some S3-related text to the *byterange.md* document.

Hopefully, this will make it easier for users to find the information they want.

## Rebuild NCZarr Testing
In order to avoid problems with running make check in parallel, two changes were made:
1. The *nczarr_test* test system was rebuilt. Now, for each test.
any generated files are kept in a test-specific directory, isolated
from all other test executions.
2. Similarly, since the S3 test bucket is shared, any generated S3 objects
are isolated using a test-specific key path.

## Other S3 Related Changes
* Add code to ensure that files created on S3 are reclaimed at end of testing.
* Used the bash "trap" command to ensure S3 cleanup even if the test fails.
* Cleanup the S3 related configure.ac flag set since S3 is used in several places. So now one should use the option *--enable-s3* instead of *--enable-nczarr-s3*, although the latter is still kept as a deprecated alias for the former.
* Get some of the github actions yml to work with S3; required fixing various test scripts adding a secret to access the Unidata S3 bucket.
* Cleanup S3 portion of libnetcdf.settings.in and netcdf_meta.h.in and test_common.in.
* Merge partial S3 support into dhttp.c.
* Create an experimental s3 access library especially for use with Windows. It is enabled by using the options *--enable-s3-internal* (automake) or *-DENABLE_S3_INTERNAL=ON* (CMake). Also add a unit-test for it.
* Move some definitions from ncrc.h to ncs3sdk.h

## Other Changes
* Provide a default implementation of strlcpy and move this and similar defaults into *dmissing.c*.
2023-04-25 17:15:06 -06:00

202 lines
5.7 KiB
C

/*
* Copyright 2018, University Corporation for Atmospheric Research
* See netcdf/COPYRIGHT file for copying and redistribution conditions.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdlib.h>
#include "netcdf.h"
#include "ncio.h"
#include "fbits.h"
#include "ncuri.h"
#include "ncrc.h"
/* With the advent of diskless io, we need to provide
for multiple ncio packages at the same time,
so we have multiple versions of ncio_create.
*/
/* Define known ncio packages */
extern int posixio_create(const char*,int,size_t,off_t,size_t,size_t*,void*,ncio**,void** const);
extern int posixio_open(const char*,int,off_t,size_t,size_t*,void*,ncio**,void** const);
extern int stdio_create(const char*,int,size_t,off_t,size_t,size_t*,void*,ncio**,void** const);
extern int stdio_open(const char*,int,off_t,size_t,size_t*,void*,ncio**,void** const);
#ifdef USE_FFIO
extern int ffio_create(const char*,int,size_t,off_t,size_t,size_t*,void*,ncio**,void** const);
extern int ffio_open(const char*,int,off_t,size_t,size_t*,void*,ncio**,void** const);
#endif
# ifdef USE_MMAP
extern int mmapio_create(const char*,int,size_t,off_t,size_t,size_t*,void*,ncio**,void** const);
extern int mmapio_open(const char*,int,off_t,size_t,size_t*,void*,ncio**,void** const);
# endif
#ifdef ENABLE_BYTERANGE
extern int httpio_open(const char*,int,off_t,size_t,size_t*,void*,ncio**,void** const);
#endif
#ifdef ENABLE_S3
extern int s3io_open(const char*,int,off_t,size_t,size_t*,void*,ncio**,void** const);
#endif
extern int memio_create(const char*,int,size_t,off_t,size_t,size_t*,void*,ncio**,void** const);
extern int memio_open(const char*,int,off_t,size_t,size_t*,void*,ncio**,void** const);
/* Forward */
#ifdef ENABLE_BYTERANGE
static int urlmodetest(const char* path);
#endif
int
ncio_create(const char *path, int ioflags, size_t initialsz,
off_t igeto, size_t igetsz, size_t *sizehintp,
void* parameters,
ncio** iopp, void** const mempp)
{
if(fIsSet(ioflags,NC_DISKLESS)) {
return memio_create(path,ioflags,initialsz,igeto,igetsz,sizehintp,parameters,iopp,mempp);
} else if(fIsSet(ioflags,NC_INMEMORY)) {
return memio_create(path,ioflags,initialsz,igeto,igetsz,sizehintp,parameters,iopp,mempp);
}
# ifdef USE_MMAP
else if(fIsSet(ioflags,NC_MMAP)) {
return mmapio_create(path,ioflags,initialsz,igeto,igetsz,sizehintp,parameters,iopp,mempp);
}
# endif /*USE_MMAP*/
#ifdef USE_STDIO
return stdio_create(path,ioflags,initialsz,igeto,igetsz,sizehintp,parameters,iopp,mempp);
#elif defined(USE_FFIO)
return ffio_create(path,ioflags,initialsz,igeto,igetsz,sizehintp,parameters,iopp,mempp);
#else
return posixio_create(path,ioflags,initialsz,igeto,igetsz,sizehintp,parameters,iopp,mempp);
#endif
}
int
ncio_open(const char *path, int ioflags,
off_t igeto, size_t igetsz, size_t *sizehintp,
void* parameters,
ncio** iopp, void** const mempp)
{
#ifdef ENABLE_BYTERANGE
int modetest = urlmodetest(path);
#endif
/* Diskless open has the following constraints:
1. file must be classic version 1 or 2 or 5
*/
if(fIsSet(ioflags,NC_DISKLESS)) {
return memio_open(path,ioflags,igeto,igetsz,sizehintp,parameters,iopp,mempp);
}
if(fIsSet(ioflags,NC_INMEMORY)) {
return memio_open(path,ioflags,igeto,igetsz,sizehintp,parameters,iopp,mempp);
}
# ifdef USE_MMAP
if(fIsSet(ioflags,NC_MMAP)) {
return mmapio_open(path,ioflags,igeto,igetsz,sizehintp,parameters,iopp,mempp);
}
# endif /*USE_MMAP*/
# ifdef ENABLE_BYTERANGE
if(modetest == NC_HTTP) {
return httpio_open(path,ioflags,igeto,igetsz,sizehintp,parameters,iopp,mempp);
}
# ifdef ENABLE_S3
if(modetest == NC_S3SDK) {
return s3io_open(path,ioflags,igeto,igetsz,sizehintp,parameters,iopp,mempp);
}
# endif
# endif /*ENABLE_BYTERANGE*/
#ifdef USE_STDIO
return stdio_open(path,ioflags,igeto,igetsz,sizehintp,parameters,iopp,mempp);
#elif defined(USE_FFIO)
return ffio_open(path,ioflags,igeto,igetsz,sizehintp,parameters,iopp,mempp);
#else
return posixio_open(path,ioflags,igeto,igetsz,sizehintp,parameters,iopp,mempp);
#endif
}
/**************************************************/
/* wrapper functions for the ncio dispatch table */
int
ncio_rel(ncio* const nciop, off_t offset, int rflags)
{
return nciop->rel(nciop,offset,rflags);
}
int
ncio_get(ncio* const nciop, off_t offset, size_t extent,
int rflags, void **const vpp)
{
return nciop->get(nciop,offset,extent,rflags,vpp);
}
int
ncio_move(ncio* const nciop, off_t to, off_t from, size_t nbytes, int rflags)
{
return nciop->move(nciop,to,from,nbytes,rflags);
}
int
ncio_sync(ncio* const nciop)
{
return nciop->sync(nciop);
}
int
ncio_filesize(ncio* const nciop, off_t *filesizep)
{
return nciop->filesize(nciop,filesizep);
}
int
ncio_pad_length(ncio* const nciop, off_t length)
{
return nciop->pad_length(nciop,length);
}
int
ncio_close(ncio* const nciop, int doUnlink)
{
/* close and release all resources associated
with nciop, including nciop
*/
int status = nciop->close(nciop,doUnlink);
return status;
}
/* URL utilities */
/*
Check mode flags and return:
NC_HTTP => byterange
NC_S3SDK => s3
0 => Not URL
*/
#ifdef ENABLE_BYTERANGE
static int
urlmodetest(const char* path)
{
int kind = 0;
NCURI* uri = NULL;
ncuriparse(path,&uri);
if(uri == NULL) return 0; /* Not URL */
if(NC_testmode(uri, "bytes")) {
/* NC_S3SDK takes priority over NC_HTTP */
if(NC_testmode(uri, "s3")) kind = NC_S3SDK; else kind = NC_HTTP;
} else
kind = 0;
ncurifree(uri);
return kind;
}
#endif