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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-04-30 10:50:13 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-05-02 12:40:06 +0200
commita85c6025903a2b6e97e1938b201b3361a0cbed66 (patch)
treecf92df4ba782c4b9c4a49dcf1cc3e25f849723a9 /lib/comp/lzma.c
parentfa7f378bf627ddcfd7a93a000149e4d8c3810bf5 (diff)
Add compressor library
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'lib/comp/lzma.c')
-rw-r--r--lib/comp/lzma.c100
1 files changed, 100 insertions, 0 deletions
diff --git a/lib/comp/lzma.c b/lib/comp/lzma.c
new file mode 100644
index 0000000..fd2a6c7
--- /dev/null
+++ b/lib/comp/lzma.c
@@ -0,0 +1,100 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <lzma.h>
+
+#include "internal.h"
+
+typedef struct {
+ compressor_t base;
+
+ size_t block_size;
+ uint8_t buffer[];
+} lzma_compressor_t;
+
+static ssize_t lzma_comp_block(compressor_t *base, uint8_t *block, size_t size)
+{
+ lzma_compressor_t *lzma = (lzma_compressor_t *)base;
+ lzma_filter filters[5];
+ lzma_options_lzma opt;
+ size_t written = 0;
+ lzma_ret ret;
+
+ if (lzma_lzma_preset(&opt, LZMA_PRESET_DEFAULT)) {
+ fputs("error initializing LZMA options\n", stderr);
+ return -1;
+ }
+
+ opt.dict_size = lzma->block_size;
+
+ filters[0].id = LZMA_FILTER_LZMA2;
+ filters[0].options = &opt;
+
+ filters[1].id = LZMA_VLI_UNKNOWN;
+ filters[1].options = NULL;
+
+ ret = lzma_stream_buffer_encode(filters, LZMA_CHECK_CRC32, NULL,
+ block, size, lzma->buffer,
+ &written, lzma->block_size);
+
+ if (ret == LZMA_OK) {
+ if (written >= size)
+ return 0;
+
+ memcpy(block, lzma->buffer, size);
+ return written;
+ }
+
+ if (ret != LZMA_BUF_ERROR) {
+ fputs("lzma block compress failed\n", stderr);
+ return -1;
+ }
+
+ return 0;
+}
+
+static ssize_t lzma_uncomp_block(compressor_t *base, uint8_t *block,
+ size_t size)
+{
+ lzma_compressor_t *lzma = (lzma_compressor_t *)base;
+ uint64_t memlimit = 32 * 1024 * 1024;
+ size_t dest_pos = 0;
+ size_t src_pos = 0;
+ lzma_ret ret;
+
+ ret = lzma_stream_buffer_decode(&memlimit, 0, NULL,
+ block, &src_pos, size,
+ lzma->buffer, &dest_pos,
+ lzma->block_size);
+
+ if (ret == LZMA_OK && size == src_pos) {
+ memcpy(block, lzma->buffer, dest_pos);
+ return (ssize_t)dest_pos;
+ }
+
+ fputs("lzma block extract failed\n", stderr);
+ return -1;
+}
+
+static void lzma_destroy(compressor_t *base)
+{
+ free(base);
+}
+
+compressor_t *create_lzma_compressor(bool compress, size_t block_size)
+{
+ lzma_compressor_t *lzma = calloc(1, sizeof(*lzma) + block_size);
+ compressor_t *base = (compressor_t *)lzma;
+
+ if (lzma == NULL) {
+ perror("creating lzma stream");
+ return NULL;
+ }
+
+ lzma->block_size = block_size;
+ base->destroy = lzma_destroy;
+ base->do_block = compress ? lzma_comp_block : lzma_uncomp_block;
+ return base;
+}