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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 21:12:04 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 21:12:04 +0000
commiteac54b7c4aec25060d7bd856f7cdc290943d6aae (patch)
tree9a6d81c9f88df4698e746d63d14ddafeddd918b8 /src/liblzma/delta/delta_common.c
parentInitial commit. (diff)
downloadxz-utils-eac54b7c4aec25060d7bd856f7cdc290943d6aae.tar.xz
xz-utils-eac54b7c4aec25060d7bd856f7cdc290943d6aae.zip
Adding upstream version 5.4.1.upstream/5.4.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/liblzma/delta/delta_common.c')
-rw-r--r--src/liblzma/delta/delta_common.c73
1 files changed, 73 insertions, 0 deletions
diff --git a/src/liblzma/delta/delta_common.c b/src/liblzma/delta/delta_common.c
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+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file delta_common.c
+/// \brief Common stuff for Delta encoder and decoder
+//
+// Author: Lasse Collin
+//
+// This file has been put into the public domain.
+// You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "delta_common.h"
+#include "delta_private.h"
+
+
+static void
+delta_coder_end(void *coder_ptr, const lzma_allocator *allocator)
+{
+ lzma_delta_coder *coder = coder_ptr;
+ lzma_next_end(&coder->next, allocator);
+ lzma_free(coder, allocator);
+ return;
+}
+
+
+extern lzma_ret
+lzma_delta_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
+ const lzma_filter_info *filters)
+{
+ // Allocate memory for the decoder if needed.
+ lzma_delta_coder *coder = next->coder;
+ if (coder == NULL) {
+ coder = lzma_alloc(sizeof(lzma_delta_coder), allocator);
+ if (coder == NULL)
+ return LZMA_MEM_ERROR;
+
+ next->coder = coder;
+
+ // End function is the same for encoder and decoder.
+ next->end = &delta_coder_end;
+ coder->next = LZMA_NEXT_CODER_INIT;
+ }
+
+ // Validate the options.
+ if (lzma_delta_coder_memusage(filters[0].options) == UINT64_MAX)
+ return LZMA_OPTIONS_ERROR;
+
+ // Set the delta distance.
+ const lzma_options_delta *opt = filters[0].options;
+ coder->distance = opt->dist;
+
+ // Initialize the rest of the variables.
+ coder->pos = 0;
+ memzero(coder->history, LZMA_DELTA_DIST_MAX);
+
+ // Initialize the next decoder in the chain, if any.
+ return lzma_next_filter_init(&coder->next, allocator, filters + 1);
+}
+
+
+extern uint64_t
+lzma_delta_coder_memusage(const void *options)
+{
+ const lzma_options_delta *opt = options;
+
+ if (opt == NULL || opt->type != LZMA_DELTA_TYPE_BYTE
+ || opt->dist < LZMA_DELTA_DIST_MIN
+ || opt->dist > LZMA_DELTA_DIST_MAX)
+ return UINT64_MAX;
+
+ return sizeof(lzma_delta_coder);
+}