decompress bx streams on the fly

diff --git a/io-xcf.c b/io-xcf.c
index abb2336..fdba1e8 100644 (file)
--- a/io-xcf.c
+++ b/io-xcf.c
@@ -45,6 +45,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <errno.h>
+#include <bzlib.h>
 
 #define LOG(...) printf (__VA_ARGS__);
 
@@ -106,12 +107,18 @@
 #define LAYERMODE_GRAINEXTRACT 20
 #define LAYERMODE_GRAINMERGE   21
 
+#define FILETYPE_UNKNOWN       0
+#define FILETYPE_XCF           1
+#define FILETYPE_XCF_BZ2       2
+
 typedef struct _XcfContext XcfContext;
 struct _XcfContext {
        GdkPixbufModuleSizeFunc size_func;
        GdkPixbufModulePreparedFunc prepare_func;
        GdkPixbufModuleUpdatedFunc update_func;
        gpointer user_data;
+       gint type;
+       bz_stream *bz_stream;
 
        gchar *tempname;
        FILE *file;
@@ -1187,6 +1194,9 @@ xcf_image_begin_load (GdkPixbufModuleSizeFunc size_func,
        context->prepare_func = prepare_func;
        context->update_func = update_func;
        context->user_data = user_data;
+       context->type = FILETYPE_UNKNOWN;
+       context->bz_stream = NULL;
+
        fd = g_file_open_tmp ("gdkpixbuf-xcf-tmp.XXXXXX", &context->tempname, NULL);
        
        if (fd < 0) {
@@ -1235,17 +1245,95 @@ xcf_image_load_increment (gpointer data,
                    GError **error)
 {
        LOG ("Increment %d\n", size);
-       XcfContext *context = (XcfContext*) data;
        g_return_val_if_fail (data, FALSE);
+       XcfContext *context = (XcfContext*) data;
 
-       if (fwrite (buf, sizeof (guchar), size, context->file) != size) {
-               gint save_errno = errno;
-               g_set_error_literal (error,
-                                    G_FILE_ERROR,
-                                    g_file_error_from_errno (save_errno),
-                                    "Failed to write to temporary file when loading Xcf image");
-               return FALSE;
+       if (context->type == FILETYPE_UNKNOWN) { // first chunk
+               if (!strncmp (buf, "gimp xcf ", 9))
+                       context->type = FILETYPE_XCF;
+               if (!strncmp (buf, "BZh", 3)) {
+                       context->type = FILETYPE_XCF_BZ2;
+
+                       //Initialize bzlib
+                       context->bz_stream = g_new (bz_stream, 1);
+                       context->bz_stream->bzalloc = NULL;
+                       context->bz_stream->bzfree = NULL;
+                       context->bz_stream->opaque = NULL;
+
+                       int ret = BZ2_bzDecompressInit (context->bz_stream, 4, 0); //Verbosity = 4, don't optimize for memory usage
+                       if (ret != BZ_OK) {
+                               g_set_error_literal (error, GDK_PIXBUF_ERROR, GDK_PIXBUF_ERROR_FAILED, "Failed to initialize bz2 decompressor");
+                               return FALSE;
+                       }
+
+               }
+               LOG ("File type %d\n", context->type);
+       }
+
+       gchar *outbuf;
+       switch (context->type) {
+       case FILETYPE_XCF_BZ2:
+               outbuf = g_new (gchar, 65536);
+               context->bz_stream->next_in = (gchar*)buf;
+               context->bz_stream->avail_in = size;
+               while (context->bz_stream->avail_in > 0) {
+                       context->bz_stream->next_out = outbuf;
+                       context->bz_stream->avail_out = 65536;
+                       LOG ("BEFORE:\tnext_in %p, avail_in %d, total_in %d, next_out %p, avail_out %d total_out %d\n",
+                                       context->bz_stream->next_in,
+                                       context->bz_stream->avail_in,
+                                       context->bz_stream->total_in_lo32,
+                                       context->bz_stream->next_out,
+                                       context->bz_stream->avail_out,
+                                       context->bz_stream->total_out_lo32);
+                       int ret = BZ2_bzDecompress (context->bz_stream);
+                       LOG ("AFTER:\tnext_in %p, avail_in %d, total_in %d, next_out %p, avail_out %d total_out %d\n",
+                                       context->bz_stream->next_in,
+                                       context->bz_stream->avail_in,
+                                       context->bz_stream->total_in_lo32,
+                                       context->bz_stream->next_out,
+                                       context->bz_stream->avail_out,
+                                       context->bz_stream->total_out_lo32);
+                       switch (ret) {
+                       case BZ_OK:
+                               break;
+                       case BZ_STREAM_END:
+                               LOG ("End of bz stream\n");
+                               BZ2_bzDecompressEnd (context->bz_stream);
+                               //FIXME set the filetype to CLOSED
+                               break;
+                       default:
+                               BZ2_bzDecompressEnd (context->bz_stream);
+                               //FIXME set the filetype to CLOSED
+                               g_set_error_literal (error, GDK_PIXBUF_ERROR, GDK_PIXBUF_ERROR_FAILED, "Failed to decompress");
+                               return FALSE;
+                       }
+
+                       int total_out = 65536 - context->bz_stream->avail_out;
+                       LOG ("Wrote %d to file %s\n", total_out, context->tempname);
+                       if (fwrite (outbuf, sizeof (guchar), total_out, context->file) != total_out) {
+                               gint save_errno = errno;
+                               g_set_error_literal (error,
+                                                    G_FILE_ERROR,
+                                                    g_file_error_from_errno (save_errno),
+                                                    "Failed to write to temporary file when loading Xcf image");
+                               return FALSE;
+                       }
+               }
+               break;
+       case FILETYPE_XCF:
+       default:
+               if (fwrite (buf, sizeof (guchar), size, context->file) != size) {
+                       gint save_errno = errno;
+                       g_set_error_literal (error,
+                                            G_FILE_ERROR,
+                                            g_file_error_from_errno (save_errno),
+                                            "Failed to write to temporary file when loading Xcf image");
+                       return FALSE;
+               }
+               break;
        }
+
        return TRUE;    
 }