ultimatepp/bazaar/plugin/gdal/gcore/gdalpamproxydb.cpp
cxl 23ff1e7e82 .gdal moved to bazaar
git-svn-id: svn://ultimatepp.org/upp/trunk@9273 f0d560ea-af0d-0410-9eb7-867de7ffcac7
2015-12-07 13:36:24 +00:00

400 lines
14 KiB
C++

/******************************************************************************
* $Id: gdalpamproxydb.cpp 28459 2015-02-12 13:48:21Z rouault $
*
* Project: GDAL Core
* Purpose: Implementation of the GDAL PAM Proxy database interface.
* The proxy db is used to associate .aux.xml files in a temp
* directory - used for files for which aux.xml files can't be
* created (ie. read-only file systems).
* Author: Frank Warmerdam, warmerdam@pobox.com
*
******************************************************************************
* Copyright (c) 2005, Frank Warmerdam <warmerdam@pobox.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
****************************************************************************/
#include "gdal_pam.h"
#include "cpl_string.h"
#include "ogr_spatialref.h"
#include "cpl_multiproc.h"
CPL_CVSID("$Id: gdalpamproxydb.cpp 28459 2015-02-12 13:48:21Z rouault $");
/************************************************************************/
/* ==================================================================== */
/* GDALPamProxyDB */
/* ==================================================================== */
/************************************************************************/
class GDALPamProxyDB
{
public:
GDALPamProxyDB() { nUpdateCounter = -1; }
CPLString osProxyDBDir;
int nUpdateCounter;
std::vector<CPLString> aosOriginalFiles;
std::vector<CPLString> aosProxyFiles;
void CheckLoadDB();
void LoadDB();
void SaveDB();
};
static int bProxyDBInitialized = FALSE;
static GDALPamProxyDB *poProxyDB = NULL;
static CPLMutex *hProxyDBLock = NULL;
/************************************************************************/
/* CheckLoadDB() */
/* */
/* Eventually we want to check if the file has changed, and if */
/* so, force it to be reloaded. TODO: */
/************************************************************************/
void GDALPamProxyDB::CheckLoadDB()
{
if( nUpdateCounter == -1 )
LoadDB();
}
/************************************************************************/
/* LoadDB() */
/* */
/* It is assumed the caller already holds the lock. */
/************************************************************************/
void GDALPamProxyDB::LoadDB()
{
/* -------------------------------------------------------------------- */
/* Open the database relating original names to proxy .aux.xml */
/* file names. */
/* -------------------------------------------------------------------- */
CPLString osDBName =
CPLFormFilename( osProxyDBDir, "gdal_pam_proxy", "dat" );
VSILFILE *fpDB = VSIFOpenL( osDBName, "r" );
nUpdateCounter = 0;
if( fpDB == NULL )
return;
/* -------------------------------------------------------------------- */
/* Read header, verify and extract update counter. */
/* -------------------------------------------------------------------- */
GByte abyHeader[100];
if( VSIFReadL( abyHeader, 1, 100, fpDB ) != 100
|| strncmp( (const char *) abyHeader, "GDAL_PROXY", 10 ) != 0 )
{
CPLError( CE_Failure, CPLE_AppDefined,
"Problem reading %s header - short or corrupt?",
osDBName.c_str() );
return;
}
nUpdateCounter = atoi((const char *) abyHeader + 10);
/* -------------------------------------------------------------------- */
/* Read the file in one gulp. */
/* -------------------------------------------------------------------- */
int nBufLength;
char *pszDBData;
VSIFSeekL( fpDB, 0, SEEK_END );
nBufLength = (int) (VSIFTellL(fpDB) - 100);
pszDBData = (char *) CPLCalloc(1,nBufLength+1);
VSIFSeekL( fpDB, 100, SEEK_SET );
VSIFReadL( pszDBData, 1, nBufLength, fpDB );
VSIFCloseL( fpDB );
/* -------------------------------------------------------------------- */
/* Parse the list of in/out names. */
/* -------------------------------------------------------------------- */
int iNext = 0;
while( iNext < nBufLength )
{
CPLString osOriginal, osProxy;
osOriginal.assign( pszDBData + iNext );
for( ; iNext < nBufLength && pszDBData[iNext] != '\0'; iNext++ ) {}
if( iNext == nBufLength )
break;
iNext++;
osProxy = osProxyDBDir;
osProxy += "/";
osProxy += pszDBData + iNext;
for( ; iNext < nBufLength && pszDBData[iNext] != '\0'; iNext++ ) {}
iNext++;
aosOriginalFiles.push_back( osOriginal );
aosProxyFiles.push_back( osProxy );
}
CPLFree( pszDBData );
}
/************************************************************************/
/* SaveDB() */
/************************************************************************/
void GDALPamProxyDB::SaveDB()
{
/* -------------------------------------------------------------------- */
/* Open the database relating original names to proxy .aux.xml */
/* file names. */
/* -------------------------------------------------------------------- */
CPLString osDBName =
CPLFormFilename( osProxyDBDir, "gdal_pam_proxy", "dat" );
void *hLock = CPLLockFile( osDBName, 1.0 );
// proceed even if lock fails - we need CPLBreakLockFile()!
if( hLock == NULL )
{
CPLError( CE_Warning, CPLE_AppDefined,
"GDALPamProxyDB::SaveDB() - Failed to lock %s file, proceeding anyways.",
osDBName.c_str() );
}
VSILFILE *fpDB = VSIFOpenL( osDBName, "w" );
if( fpDB == NULL )
{
if( hLock )
CPLUnlockFile( hLock );
CPLError( CE_Failure, CPLE_AppDefined,
"Failed to save %s Pam Proxy DB.\n%s",
osDBName.c_str(),
VSIStrerror( errno ) );
return;
}
/* -------------------------------------------------------------------- */
/* Write header. */
/* -------------------------------------------------------------------- */
GByte abyHeader[100];
memset( abyHeader, ' ', sizeof(abyHeader) );
strncpy( (char *) abyHeader, "GDAL_PROXY", 10 );
sprintf( (char *) abyHeader + 10, "%9d", nUpdateCounter );
VSIFWriteL( abyHeader, 1, 100, fpDB );
/* -------------------------------------------------------------------- */
/* Write names. */
/* -------------------------------------------------------------------- */
unsigned int i;
for( i = 0; i < aosOriginalFiles.size(); i++ )
{
size_t nBytesWritten;
const char *pszProxyFile;
VSIFWriteL( aosOriginalFiles[i].c_str(), 1,
strlen(aosOriginalFiles[i].c_str())+1, fpDB );
pszProxyFile = CPLGetFilename(aosProxyFiles[i]);
nBytesWritten = VSIFWriteL( pszProxyFile, 1,
strlen(pszProxyFile)+1, fpDB );
if( nBytesWritten != strlen(pszProxyFile)+1 )
{
CPLError( CE_Failure, CPLE_AppDefined,
"Failed to write complete %s Pam Proxy DB.\n%s",
osDBName.c_str(),
VSIStrerror( errno ) );
VSIFCloseL( fpDB );
VSIUnlink( osDBName );
return;
}
}
VSIFCloseL( fpDB );
if( hLock )
CPLUnlockFile( hLock );
}
/************************************************************************/
/* InitProxyDB() */
/* */
/* Initialize ProxyDB (if it isn't already initialized). */
/************************************************************************/
static void InitProxyDB()
{
if( !bProxyDBInitialized )
{
CPLMutexHolderD( &hProxyDBLock );
if( !bProxyDBInitialized )
{
const char *pszProxyDir =
CPLGetConfigOption( "GDAL_PAM_PROXY_DIR", NULL );
if( pszProxyDir )
{
poProxyDB = new GDALPamProxyDB();
poProxyDB->osProxyDBDir = pszProxyDir;
}
}
bProxyDBInitialized = TRUE;
}
}
/************************************************************************/
/* PamCleanProxyDB() */
/************************************************************************/
void PamCleanProxyDB()
{
{
CPLMutexHolderD( &hProxyDBLock );
bProxyDBInitialized = FALSE;
delete poProxyDB;
poProxyDB = NULL;
}
CPLDestroyMutex( hProxyDBLock );
hProxyDBLock = NULL;
}
/************************************************************************/
/* PamGetProxy() */
/************************************************************************/
const char *PamGetProxy( const char *pszOriginal )
{
InitProxyDB();
if( poProxyDB == NULL )
return NULL;
CPLMutexHolderD( &hProxyDBLock );
unsigned int i;
poProxyDB->CheckLoadDB();
for( i = 0; i < poProxyDB->aosOriginalFiles.size(); i++ )
{
if( strcmp( poProxyDB->aosOriginalFiles[i], pszOriginal ) == 0 )
return poProxyDB->aosProxyFiles[i];
}
return NULL;
}
/************************************************************************/
/* PamAllocateProxy() */
/************************************************************************/
const char *PamAllocateProxy( const char *pszOriginal )
{
InitProxyDB();
if( poProxyDB == NULL )
return NULL;
CPLMutexHolderD( &hProxyDBLock );
poProxyDB->CheckLoadDB();
/* -------------------------------------------------------------------- */
/* Form the proxy filename based on the original path if */
/* possible, but dummy out any questionable characters, path */
/* delimiters and such. This is intended to make the proxy */
/* name be identifiable by folks digging around in the proxy */
/* database directory. */
/* */
/* We also need to be careful about length. */
/* -------------------------------------------------------------------- */
CPLString osRevProxyFile;
int i;
i = strlen(pszOriginal) - 1;
while( i >= 0 && osRevProxyFile.size() < 220 )
{
if( i > 6 && EQUALN(pszOriginal+i-5,":::OVR",6) )
i -= 6;
// make some effort to break long names at path delimiters.
if( (pszOriginal[i] == '/' || pszOriginal[i] == '\\')
&& osRevProxyFile.size() > 200 )
break;
if( (pszOriginal[i] >= 'A' && pszOriginal[i] <= 'Z')
|| (pszOriginal[i] >= 'a' && pszOriginal[i] <= 'z')
|| (pszOriginal[i] >= '0' && pszOriginal[i] <= '9')
|| pszOriginal[i] == '.' )
osRevProxyFile += pszOriginal[i];
else
osRevProxyFile += '_';
i--;
}
CPLString osOriginal = pszOriginal;
CPLString osProxy;
CPLString osCounter;
osProxy = poProxyDB->osProxyDBDir + "/";
osCounter.Printf( "%06d_", poProxyDB->nUpdateCounter++ );
osProxy += osCounter;
for( i = osRevProxyFile.size()-1; i >= 0; i-- )
osProxy += osRevProxyFile[i];
if( osOriginal.find(":::OVR") != CPLString::npos )
osProxy += ".ovr";
else
osProxy += ".aux.xml";
/* -------------------------------------------------------------------- */
/* Add the proxy and the original to the proxy list and resave */
/* the database. */
/* -------------------------------------------------------------------- */
poProxyDB->aosOriginalFiles.push_back( osOriginal );
poProxyDB->aosProxyFiles.push_back( osProxy );
poProxyDB->SaveDB();
return PamGetProxy( pszOriginal );
}