preliminary step implementing virtual fileio

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

1 files changed, 167 insertions, 0 deletions

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);
+}