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-rwxr-xr-xjpeg/jcomapi.c106
1 files changed, 106 insertions, 0 deletions
diff --git a/jpeg/jcomapi.c b/jpeg/jcomapi.c
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+/*
+ * jcomapi.c
+ *
+ * Copyright (C) 1994-1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains application interface routines that are used for both
+ * compression and decompression.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+
+
+/*
+ * Abort processing of a JPEG compression or decompression operation,
+ * but don't destroy the object itself.
+ *
+ * For this, we merely clean up all the nonpermanent memory pools.
+ * Note that temp files (virtual arrays) are not allowed to belong to
+ * the permanent pool, so we will be able to close all temp files here.
+ * Closing a data source or destination, if necessary, is the application's
+ * responsibility.
+ */
+
+GLOBAL(void)
+jpeg_abort (j_common_ptr cinfo)
+{
+ int pool;
+
+ /* Do nothing if called on a not-initialized or destroyed JPEG object. */
+ if (cinfo->mem == NULL)
+ return;
+
+ /* Releasing pools in reverse order might help avoid fragmentation
+ * with some (brain-damaged) malloc libraries.
+ */
+ for (pool = JPOOL_NUMPOOLS-1; pool > JPOOL_PERMANENT; pool--) {
+ (*cinfo->mem->free_pool) (cinfo, pool);
+ }
+
+ /* Reset overall state for possible reuse of object */
+ if (cinfo->is_decompressor) {
+ cinfo->global_state = DSTATE_START;
+ /* Try to keep application from accessing now-deleted marker list.
+ * A bit kludgy to do it here, but this is the most central place.
+ */
+ ((j_decompress_ptr) cinfo)->marker_list = NULL;
+ } else {
+ cinfo->global_state = CSTATE_START;
+ }
+}
+
+
+/*
+ * Destruction of a JPEG object.
+ *
+ * Everything gets deallocated except the master jpeg_compress_struct itself
+ * and the error manager struct. Both of these are supplied by the application
+ * and must be freed, if necessary, by the application. (Often they are on
+ * the stack and so don't need to be freed anyway.)
+ * Closing a data source or destination, if necessary, is the application's
+ * responsibility.
+ */
+
+GLOBAL(void)
+jpeg_destroy (j_common_ptr cinfo)
+{
+ /* We need only tell the memory manager to release everything. */
+ /* NB: mem pointer is NULL if memory mgr failed to initialize. */
+ if (cinfo->mem != NULL)
+ (*cinfo->mem->self_destruct) (cinfo);
+ cinfo->mem = NULL; /* be safe if jpeg_destroy is called twice */
+ cinfo->global_state = 0; /* mark it destroyed */
+}
+
+
+/*
+ * Convenience routines for allocating quantization and Huffman tables.
+ * (Would jutils.c be a more reasonable place to put these?)
+ */
+
+GLOBAL(JQUANT_TBL *)
+jpeg_alloc_quant_table (j_common_ptr cinfo)
+{
+ JQUANT_TBL *tbl;
+
+ tbl = (JQUANT_TBL *)
+ (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JQUANT_TBL));
+ tbl->sent_table = FALSE; /* make sure this is false in any new table */
+ return tbl;
+}
+
+
+GLOBAL(JHUFF_TBL *)
+jpeg_alloc_huff_table (j_common_ptr cinfo)
+{
+ JHUFF_TBL *tbl;
+
+ tbl = (JHUFF_TBL *)
+ (*cinfo->mem->alloc_small) (cinfo, JPOOL_PERMANENT, SIZEOF(JHUFF_TBL));
+ tbl->sent_table = FALSE; /* make sure this is false in any new table */
+ return tbl;
+}