netcdf-c/libdap4/d4read.c

/*! \file

Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014,
2015, 2016, 2017, 2018
University Corporation for Atmospheric Research/Unidata.

See \ref copyright file for more info.

*/

#include "d4includes.h"
#include "d4curlfunctions.h"
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#include "ncpathmgr.h"

/* Do conversion if this code was compiled via Vis. Studio or Mingw */

/*Forward*/
static int readpacket(NCD4INFO* state, NCURI*, NCbytes*, NCD4mode, long*);
static int readfile(NCD4INFO* state, const NCURI*, const char* suffix, NCbytes* packet);
static int readfiletofile(NCD4INFO* state, const NCURI*, const char* suffix, FILE* stream, d4size_t*);

#ifdef HAVE_GETTIMEOFDAY
static double
deltatime(struct timeval time0,struct timeval time1)
{
    double t0, t1;
    t0 = ((double)time0.tv_sec);
    t0 += ((double)time0.tv_usec) / 1000000.0;
    t1 = ((double)time1.tv_sec);
    t1 += ((double)time1.tv_usec) / 1000000.0;
    return (t1 - t0);
}
#endif

int
NCD4_readDMR(NCD4INFO* state)
{
    int stat = NC_NOERR;
    long lastmodified = -1;

    stat = readpacket(state,state->uri,state->curl->packet,NCD4_DMR,&lastmodified);
    if(stat == NC_NOERR)
	state->data.dmrlastmodified = lastmodified;
    return THROW(stat);
}

int
NCD4_readDAP(NCD4INFO* state, int flags)
{
    int stat = NC_NOERR;
    long lastmod = -1;

    if((flags & NCF_ONDISK) == 0) {
        stat = readpacket(state,state->uri,state->curl->packet,NCD4_DAP,&lastmod);
        if(stat == NC_NOERR)
            state->data.daplastmodified = lastmod;
    } else { /*((flags & NCF_ONDISK) != 0) */
        NCURI* url = state->uri;
        int fileprotocol = (strcmp(url->protocol,"file")==0);
        if(fileprotocol) {
            stat = readfiletofile(state, url, ".dap", state->data.ondiskfile, &state->data.datasize);
        } else {
	    char* readurl = NULL;
            int flags = 0;
            if(!fileprotocol) flags |= NCURIQUERY;
            flags |= NCURIENCODE;
	    flags |= NCURIPWD;
#ifdef FIX
            ncurisetconstraints(url,state->constraint);
#endif
	    readurl = ncuribuild(url,NULL,".dods",NCURISVC);
	    if(readurl == NULL)
		return THROW(NC_ENOMEM);
            stat = NCD4_fetchurl_file(state->curl, readurl, state->data.ondiskfile,
                                   &state->data.datasize, &lastmod);
            nullfree(readurl);
            if(stat == NC_NOERR)
                state->data.daplastmodified = lastmod;
        }
    }
    return THROW(stat);
}

static const char*
dxxextension(int dxx)
{
    switch(dxx) {
    case NCD4_DMR: return ".dmr";
    case NCD4_DAP: return ".dap";
    default: break;
    }
    return NULL;
}

static int
readpacket(NCD4INFO* state, NCURI* url, NCbytes* packet, NCD4mode dxx, long* lastmodified)
{
    int stat = NC_NOERR;
    int fileprotocol = 0;
    const char* suffix = dxxextension(dxx);
    CURL* curl = state->curl->curl;
#ifdef HAVE_GETTIMEOFDAY
    struct timeval time0;
    struct timeval time1;
#endif

    fileprotocol = (strcmp(url->protocol,"file")==0);

    if(fileprotocol) {
	/* Short circuit file://... urls*/
	/* We do this because the test code always needs to read files*/
	stat = readfile(state, url,suffix,packet);
    } else {
        char* fetchurl = NULL;
	int flags = NCURIBASE;
	if(!fileprotocol) flags |= NCURIQUERY;
	flags |= NCURIENCODE;
        fetchurl = ncuribuild(url,NULL,suffix,flags);
	MEMCHECK(fetchurl);
	if(FLAGSET(state->controls.flags,NCF_SHOWFETCH)) {
	    nclog(NCLOGDBG,"fetch url=%s",fetchurl);
#ifdef HAVE_GETTIMEOFDAY
   	    gettimeofday(&time0,NULL);
#endif
	}
        stat = NCD4_fetchurl(curl,fetchurl,packet,lastmodified);
        nullfree(fetchurl);
	if(stat) goto fail;
	if(FLAGSET(state->controls.flags,NCF_SHOWFETCH)) {
            double secs = 0;
#ifdef HAVE_GETTIMEOFDAY
   	    gettimeofday(&time1,NULL);
	    secs = deltatime(time0,time1);
#endif
            nclog(NCLOGDBG,"fetch complete: %0.3f",secs);
	}
    }
#ifdef D4DEBUG
  {
fprintf(stderr,"readpacket: packet.size=%lu\n",
		(unsigned long)ncbyteslength(packet));
  }
#endif
fail:
    return THROW(stat);
}

static int
readfiletofile(NCD4INFO* state, const NCURI* uri, const char* suffix, FILE* stream, d4size_t* sizep)
{
    int stat = NC_NOERR;
    NCbytes* packet = ncbytesnew();
    size_t len;
    stat = readfile(state, uri,suffix,packet);
#ifdef D4DEBUG
fprintf(stderr,"readfiletofile: packet.size=%lu\n",
		(unsigned long)ncbyteslength(packet));
#endif
    if(stat != NC_NOERR) goto unwind;
    len = nclistlength(packet);
    if(stat == NC_NOERR) {
	size_t written;
        fseek(stream,0,SEEK_SET);
	written = fwrite(ncbytescontents(packet),1,len,stream);
	if(written != len) {
#ifdef D4DEBUG
fprintf(stderr,"readfiletofile: written!=length: %lu :: %lu\n",
	(unsigned long)written,(unsigned long)len);
#endif
	    stat = NC_EIO;
	}
    }
    if(sizep != NULL) *sizep = len;
unwind:
    ncbytesfree(packet);
    return THROW(stat);
}

static int
readfile(NCD4INFO* state, const NCURI* uri, const char* suffix, NCbytes* packet)
{
    int stat = NC_NOERR;
    NCbytes* tmp = ncbytesnew();
    char* filename = NULL;

    ncbytescat(tmp,uri->path);
    if(suffix != NULL) ncbytescat(tmp,suffix);
    ncbytesnull(tmp);
    filename = ncbytesextract(tmp);
    ncbytesfree(tmp);
#ifdef HAVE_GETTIMEOFDAY
    struct timeval time0;
    struct timeval time1;
#endif

    state->fileproto.filename = filename; /* filename is alloc'd here anyway */

    if(FLAGSET(state->controls.flags,NCF_SHOWFETCH)) {
	char* surl = NULL;
#ifdef HAVE_GETTIMEOFDAY
	gettimeofday(&time0,NULL);
#endif
        surl = ncuribuild((NCURI*)uri,NULL,NULL,NCURIALL);
	nclog(NCLOGDBG,"fetch uri=%s file=%s",surl,filename);
    }
    stat = NC_readfile(filename,packet);
    if(FLAGSET(state->controls.flags,NCF_SHOWFETCH)) {
	double secs;
#ifdef HAVE_GETTIMEOFDAY
   	gettimeofday(&time1,NULL);
	secs = deltatime(time0,time1);
#endif
        nclog(NCLOGDBG,"fetch complete: %0.3f",secs);
    }
    return THROW(stat);
}