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-rw-r--r--src/journal/compress.c208
1 files changed, 208 insertions, 0 deletions
diff --git a/src/journal/compress.c b/src/journal/compress.c
new file mode 100644
index 0000000000..ff906581f0
--- /dev/null
+++ b/src/journal/compress.c
@@ -0,0 +1,208 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2011 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <lzma.h>
+
+#include "compress.h"
+
+bool compress_blob(const void *src, uint64_t src_size, void *dst, uint64_t *dst_size) {
+ lzma_stream s = LZMA_STREAM_INIT;
+ lzma_ret ret;
+ bool b = false;
+
+ assert(src);
+ assert(src_size > 0);
+ assert(dst);
+ assert(dst_size);
+
+ /* Returns false if we couldn't compress the data or the
+ * compressed result is longer than the original */
+
+ ret = lzma_easy_encoder(&s, LZMA_PRESET_DEFAULT, LZMA_CHECK_NONE);
+ if (ret != LZMA_OK)
+ return false;
+
+ s.next_in = src;
+ s.avail_in = src_size;
+ s.next_out = dst;
+ s.avail_out = src_size;
+
+ /* Does it fit? */
+ if (lzma_code(&s, LZMA_FINISH) != LZMA_STREAM_END)
+ goto fail;
+
+ /* Is it actually shorter? */
+ if (s.avail_out == 0)
+ goto fail;
+
+ *dst_size = src_size - s.avail_out;
+ b = true;
+
+fail:
+ lzma_end(&s);
+
+ return b;
+}
+
+bool uncompress_blob(const void *src, uint64_t src_size,
+ void **dst, uint64_t *dst_alloc_size, uint64_t* dst_size) {
+
+ lzma_stream s = LZMA_STREAM_INIT;
+ lzma_ret ret;
+ bool b = false;
+
+ assert(src);
+ assert(src_size > 0);
+ assert(dst);
+ assert(dst_alloc_size);
+ assert(dst_size);
+ assert(*dst_alloc_size == 0 || *dst);
+
+ ret = lzma_stream_decoder(&s, UINT64_MAX, 0);
+ if (ret != LZMA_OK)
+ return false;
+
+ if (*dst_alloc_size <= src_size) {
+ void *p;
+
+ p = realloc(*dst, src_size*2);
+ if (!p)
+ return false;
+
+ *dst = p;
+ *dst_alloc_size = src_size*2;
+ }
+
+ s.next_in = src;
+ s.avail_in = src_size;
+
+ s.next_out = *dst;
+ s.avail_out = *dst_alloc_size;
+
+ for (;;) {
+ void *p;
+
+ ret = lzma_code(&s, LZMA_FINISH);
+
+ if (ret == LZMA_STREAM_END)
+ break;
+
+ if (ret != LZMA_OK)
+ goto fail;
+
+ p = realloc(*dst, *dst_alloc_size*2);
+ if (!p)
+ goto fail;
+
+ s.next_out = (uint8_t*) p + ((uint8_t*) s.next_out - (uint8_t*) *dst);
+ s.avail_out += *dst_alloc_size;
+
+ *dst = p;
+ *dst_alloc_size *= 2;
+ }
+
+ *dst_size = *dst_alloc_size - s.avail_out;
+ b = true;
+
+fail:
+ lzma_end(&s);
+
+ return b;
+}
+
+bool uncompress_startswith(const void *src, uint64_t src_size,
+ void **buffer, uint64_t *buffer_size,
+ const void *prefix, uint64_t prefix_len,
+ uint8_t extra) {
+
+ lzma_stream s = LZMA_STREAM_INIT;
+ lzma_ret ret;
+ bool b = false;
+
+ /* Checks whether the uncompressed blob starts with the
+ * mentioned prefix. The byte extra needs to follow the
+ * prefix */
+
+ assert(src);
+ assert(src_size > 0);
+ assert(buffer);
+ assert(buffer_size);
+ assert(prefix);
+ assert(*buffer_size == 0 || *buffer);
+
+ ret = lzma_stream_decoder(&s, UINT64_MAX, 0);
+ if (ret != LZMA_OK)
+ return false;
+
+ if (*buffer_size <= prefix_len) {
+ void *p;
+
+ p = realloc(*buffer, prefix_len*2);
+ if (!p)
+ return false;
+
+ *buffer = p;
+ *buffer_size = prefix_len*2;
+ }
+
+ s.next_in = src;
+ s.avail_in = src_size;
+
+ s.next_out = *buffer;
+ s.avail_out = *buffer_size;
+
+ for (;;) {
+ void *p;
+
+ ret = lzma_code(&s, LZMA_FINISH);
+
+ if (ret != LZMA_STREAM_END && ret != LZMA_OK)
+ goto fail;
+
+ if ((*buffer_size - s.avail_out > prefix_len) &&
+ memcmp(*buffer, prefix, prefix_len) == 0 &&
+ ((const uint8_t*) *buffer)[prefix_len] == extra)
+ break;
+
+ if (ret == LZMA_STREAM_END)
+ goto fail;
+
+ p = realloc(*buffer, *buffer_size*2);
+ if (!p)
+ goto fail;
+
+ s.next_out = (uint8_t*) p + ((uint8_t*) s.next_out - (uint8_t*) *buffer);
+ s.avail_out += *buffer_size;
+
+ *buffer = p;
+ *buffer_size *= 2;
+ }
+
+ b = true;
+
+fail:
+ lzma_end(&s);
+
+ return b;
+}