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Diffstat (limited to 'subversion/libsvn_subr/compress_lz4.c')
| -rw-r--r-- | subversion/libsvn_subr/compress_lz4.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/subversion/libsvn_subr/compress_lz4.c b/subversion/libsvn_subr/compress_lz4.c new file mode 100644 index 000000000000..d700b3215566 --- /dev/null +++ b/subversion/libsvn_subr/compress_lz4.c @@ -0,0 +1,144 @@ +/* + * compress_lz4.c: LZ4 data compression routines + * + * ==================================================================== + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + * ==================================================================== + */ + +#include <assert.h> + +#include "private/svn_subr_private.h" + +#include "svn_private_config.h" + +#if SVN_INTERNAL_LZ4 +#include "lz4/lz4internal.h" +#else +#include <lz4.h> +#endif + +svn_error_t * +svn__compress_lz4(const void *data, apr_size_t len, + svn_stringbuf_t *out) +{ + apr_size_t hdrlen; + unsigned char buf[SVN__MAX_ENCODED_UINT_LEN]; + unsigned char *p; + int compressed_data_len; + int max_compressed_data_len; + + assert(len <= LZ4_MAX_INPUT_SIZE); + + p = svn__encode_uint(buf, (apr_uint64_t)len); + hdrlen = p - buf; + max_compressed_data_len = LZ4_compressBound((int)len); + svn_stringbuf_setempty(out); + svn_stringbuf_ensure(out, max_compressed_data_len + hdrlen); + svn_stringbuf_appendbytes(out, (const char *)buf, hdrlen); + compressed_data_len = LZ4_compress_default(data, out->data + out->len, + (int)len, max_compressed_data_len); + if (!compressed_data_len) + return svn_error_create(SVN_ERR_LZ4_COMPRESSION_FAILED, NULL, NULL); + + if (compressed_data_len >= (int)len) + { + /* Compression didn't help :(, just append the original text */ + svn_stringbuf_appendbytes(out, data, len); + } + else + { + out->len += compressed_data_len; + out->data[out->len] = 0; + } + + return SVN_NO_ERROR; +} + +svn_error_t * +svn__decompress_lz4(const void *data, apr_size_t len, + svn_stringbuf_t *out, + apr_size_t limit) +{ + apr_size_t hdrlen; + int compressed_data_len; + int decompressed_data_len; + apr_uint64_t u64; + const unsigned char *p = data; + int rv; + + assert(len <= INT_MAX); + assert(limit <= INT_MAX); + + /* First thing in the string is the original length. */ + p = svn__decode_uint(&u64, p, p + len); + if (p == NULL) + return svn_error_create(SVN_ERR_SVNDIFF_INVALID_COMPRESSED_DATA, NULL, + _("Decompression of compressed data failed: " + "no size")); + if (u64 > limit) + return svn_error_create(SVN_ERR_SVNDIFF_INVALID_COMPRESSED_DATA, NULL, + _("Decompression of compressed data failed: " + "size too large")); + decompressed_data_len = (int)u64; + hdrlen = p - (const unsigned char *)data; + compressed_data_len = (int)(len - hdrlen); + + svn_stringbuf_setempty(out); + svn_stringbuf_ensure(out, decompressed_data_len); + + if (compressed_data_len == decompressed_data_len) + { + /* Data is in the original, uncompressed form. */ + memcpy(out->data, p, decompressed_data_len); + } + else + { + rv = LZ4_decompress_safe((const char *)p, out->data, compressed_data_len, + decompressed_data_len); + if (rv < 0) + return svn_error_create(SVN_ERR_LZ4_DECOMPRESSION_FAILED, NULL, NULL); + + if (rv != decompressed_data_len) + return svn_error_create(SVN_ERR_SVNDIFF_INVALID_COMPRESSED_DATA, + NULL, + _("Size of uncompressed data " + "does not match stored original length")); + } + + out->data[decompressed_data_len] = 0; + out->len = decompressed_data_len; + + return SVN_NO_ERROR; +} + +const char * +svn_lz4__compiled_version(void) +{ + static const char lz4_version_str[] = APR_STRINGIFY(LZ4_VERSION_MAJOR) "." \ + APR_STRINGIFY(LZ4_VERSION_MINOR) "." \ + APR_STRINGIFY(LZ4_VERSION_RELEASE); + + return lz4_version_str; +} + +int +svn_lz4__runtime_version(void) +{ + return LZ4_versionNumber(); +} |