preliminary step implementing virtual fileio

git-svn-id: http://svn.osgeo.org/metacrs/proj/trunk@2344 4e78687f-474d-0410-85f9-8d5e500ac6b2

5 files changed, 193 insertions, 1 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index c1d1998a..dab00b3b 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -57,7 +57,7 @@ libproj_la_SOURCES = \
 	pj_open_lib.c pj_param.c pj_phi2.c pj_pr_list.c \
 	pj_qsfn.c pj_strerrno.c pj_tsfn.c pj_units.c pj_ctx.c pj_log.c \
 	pj_zpoly1.c rtodms.c vector1.c pj_release.c pj_gauss.c \
-	PJ_healpix.c PJ_natearth.c \
+	PJ_healpix.c PJ_natearth.c pj_fileapi.c \
 	\
 	pj_gc_reader.c pj_gridcatalog.c \
 	nad_cvt.c nad_init.c nad_intr.c emess.c emess.h \
diff --git a/src/pj_ctx.c b/src/pj_ctx.c
index a9dc7ab8..ccd2292c 100644
--- a/src/pj_ctx.c
+++ b/src/pj_ctx.c
@@ -73,6 +73,7 @@ projCtx pj_get_default_ctx()
         default_context.debug_level = PJ_LOG_NONE;
         default_context.logger = pj_stderr_logger;
         default_context.app_data = NULL;
+        default_context.fileapi = pj_get_default_fileapi();
 
         if( getenv("PROJ_DEBUG") != NULL )
         {
diff --git a/src/pj_fileapi.c b/src/pj_fileapi.c
new file mode 100644
index 00000000..1a1a0f21
--- /dev/null
+++ b/src/pj_fileapi.c
@@ -0,0 +1,167 @@
+/******************************************************************************
+ * $Id$
+ *
+ * Project:  PROJ.4
+ * Purpose:  Implementation of the pj_ctx_* file api, and the default stdio
+ *           based implementation.
+ * Author:   Frank Warmerdam, warmerdam@pobox.com
+ *
+ ******************************************************************************
+ * Copyright (c) 2013, Frank Warmerdam
+ *
+ * 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 <projects.h>
+#include <string.h>
+
+PJ_CVSID("$Id$");
+
+static PAFile pj_stdio_fopen(projCtx ctx, const char *filename, 
+                             const char *access);
+static size_t pj_stdio_fread(void *buffer, size_t size, size_t nmemb, 
+                             PAFile file);
+static int pj_stdio_fseek(PAFile file, long offset, int whence);
+static long pj_stdio_ftell(PAFile file);
+static void pj_stdio_fclose(PAFile file);
+
+static projFileAPI default_fileapi = { 
+    pj_stdio_fopen, 
+    pj_stdio_fread,
+    pj_stdio_fseek,
+    pj_stdio_ftell,
+    pj_stdio_fclose
+};
+
+typedef struct {
+    projCtx ctx;
+    FILE *fp;
+} stdio_pafile;
+
+/************************************************************************/
+/*                       pj_get_default_fileapi()                       */
+/************************************************************************/
+
+projFileAPI *pj_get_default_fileapi() 
+{
+    return &default_fileapi;
+}
+
+/************************************************************************/
+/*                           pj_stdio_fopen()                           */
+/************************************************************************/
+
+static PAFile pj_stdio_fopen(projCtx ctx, const char *filename, 
+                             const char *access)
+{
+    FILE *fp;
+
+    fp = fopen(filename, access);
+    if (fp == NULL) 
+    {
+        return NULL;
+    }
+
+    stdio_pafile *pafile = (stdio_pafile *) malloc(sizeof(stdio_pafile));
+    pafile->fp = fp;
+    pafile->ctx = ctx;
+    return (PAFile) pafile;
+}
+
+/************************************************************************/
+/*                           pj_stdio_fread()                           */
+/************************************************************************/
+
+static size_t pj_stdio_fread(void *buffer, size_t size, size_t nmemb, 
+                             PAFile file)
+{
+    stdio_pafile *pafile = (stdio_pafile *) file;
+    return fread(buffer, size, nmemb, pafile->fp);
+}
+
+/************************************************************************/
+/*                           pj_stdio_fseek()                           */
+/************************************************************************/
+static int pj_stdio_fseek(PAFile file, long offset, int whence)
+{
+    stdio_pafile *pafile = (stdio_pafile *) file;
+    return fseek(pafile->fp, offset, whence);
+}
+
+/************************************************************************/
+/*                           pj_stdio_ftell()                           */
+/************************************************************************/
+static long pj_stdio_ftell(PAFile file)
+{
+    stdio_pafile *pafile = (stdio_pafile *) file;
+    return ftell(pafile->fp);
+}
+
+/************************************************************************/
+/*                          pj_stdio_fclose()                           */
+/************************************************************************/
+static void pj_stdio_fclose(PAFile file)
+{
+    stdio_pafile *pafile = (stdio_pafile *) file;
+    fclose(pafile->fp);
+    free(pafile);
+}
+
+/************************************************************************/
+/*                            pj_ctx_fopen()                            */
+/*                                                                      */
+/*      Open a file using the provided file io hooks.                   */
+/************************************************************************/
+
+PAFile pj_ctx_fopen(projCtx ctx, const char *filename, const char *access)
+{
+    return ctx->fileapi->FOpen(ctx, filename, access);
+}
+
+/************************************************************************/
+/*                            pj_ctx_fread()                            */
+/************************************************************************/
+size_t pj_ctx_fread(projCtx ctx, void *buffer, size_t size, size_t nmemb, PAFile file)
+{
+    return ctx->fileapi->FRead(buffer, size, nmemb, file);
+}
+
+/************************************************************************/
+/*                            pj_ctx_fseek()                            */
+/************************************************************************/
+int    pj_ctx_fseek(projCtx ctx, PAFile file, long offset, int whence)
+{
+    return ctx->fileapi->FSeek(file, offset, whence);
+}
+
+/************************************************************************/
+/*                            pj_ctx_ftell()                            */
+/************************************************************************/
+long   pj_ctx_ftell(projCtx ctx, PAFile file)
+{
+    return ctx->fileapi->FTell(file);
+}
+
+/************************************************************************/
+/*                           pj_ctx_fclose()                            */
+/************************************************************************/
+void   pj_ctx_fclose(projCtx ctx, PAFile file)
+{
+    ctx->fileapi->FClose(file);
+}
diff --git a/src/proj_api.h b/src/proj_api.h
index feae9aff..edc3b587 100644
--- a/src/proj_api.h
+++ b/src/proj_api.h
@@ -63,6 +63,16 @@ extern int pj_errno;	/* global error return code */
 #   define projLP       LP
 #endif
 
+/* file reading api, like stdio */
+typedef int *PAFile;
+typedef struct projFileAPI_t {
+    PAFile  (*FOpen)(projCtx ctx, const char *filename, const char *access);
+    size_t  (*FRead)(void *buffer, size_t size, size_t nmemb, PAFile file);
+    int     (*FSeek)(PAFile file, long offset, int whence);
+    long    (*FTell)(PAFile file);
+    void    (*FClose)(PAFile);
+} projFileAPI;
+
 /* procedure prototypes */
 
 projXY pj_fwd(projLP, projPJ);
@@ -117,6 +127,10 @@ void pj_ctx_set_debug( projCtx, int );
 void pj_ctx_set_logger( projCtx, void (*)(void *, int, const char *) );
 void pj_ctx_set_app_data( projCtx, void * );
 void *pj_ctx_get_app_data( projCtx );
+void pj_ctx_set_file( projCtx, projFileAPI *);
+projFileAPI *pj_ctx_get_fileapi( projCtx );
+
+projFileAPI *pj_get_default_fileapi();
 
 void pj_log( projCtx ctx, int level, const char *fmt, ... );
 void pj_stderr_logger( void *, int, const char * );
diff --git a/src/projects.h b/src/projects.h
index f9dcea64..fc64ba59 100644
--- a/src/projects.h
+++ b/src/projects.h
@@ -125,12 +125,15 @@ extern double hypot(double, double);
 #define DIR_CHAR '/'
 #endif
 
+struct projFileAPI_t;
+
 /* proj thread context */
 typedef struct {
     int	    last_errno;
     int     debug_level;
     void    (*logger)(void *, int, const char *);
     void    *app_data;
+    struct projFileAPI_t *fileapi;
 } projCtx_t;
 
 /* datum_type values */
@@ -391,6 +394,13 @@ typedef struct _PJ_GridCatalog {
 } PJ_GridCatalog;
 
 
+/* file api */
+PAFile pj_ctx_fopen(projCtx ctx, const char *filename, const char *access);
+size_t pj_ctx_fread(projCtx ctx, void *buffer, size_t size, size_t nmemb, PAFile file);
+int    pj_ctx_fseek(projCtx ctx, PAFile file, long offset, int whence);
+long   pj_ctx_ftell(projCtx ctx, PAFile file);
+void   pj_ctx_fclose(projCtx ctx, PAFile file);
+
 /* procedure prototypes */
 double dmstor(const char *, char **);
 double dmstor_ctx(projCtx ctx, const char *, char **);