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// Copyright (C) 2019 Joel Rosdahl and other contributors
//
// See doc/AUTHORS.adoc for a complete list of contributors.
//
// This program 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 3 of the License, or (at your option)
// any later version.
//
// This program 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
// this program; if not, write to the Free Software Foundation, Inc., 51
// Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
#include "ccache.hpp"
#include "int_bytes_conversion.hpp"
#include "common_header.hpp"
bool
common_header_initialize_for_writing(
struct common_header *header,
FILE *output,
const char magic[4],
uint8_t version,
uint8_t compression_type,
int8_t compression_level,
uint64_t content_size,
XXH64_state_t *checksum,
struct compressor **compressor,
struct compr_state **compr_state)
{
memcpy(header->magic, magic, 4);
header->version = version;
header->compression_type = compression_type;
header->compression_level = compression_level;
header->content_size = content_size;
XXH64_reset(checksum, 0);
*compressor = compressor_from_type(header->compression_type);
assert(*compressor);
*compr_state =
(*compressor)->init(output, header->compression_level, checksum);
if (!*compr_state) {
cc_log("Failed to initialize compressor");
return false;
}
header->compression_level =
(*compressor)->get_actual_compression_level(*compr_state);
uint8_t header_bytes[COMMON_HEADER_SIZE];
memcpy(header_bytes, header->magic, 4);
header_bytes[4] = header->version;
header_bytes[5] = header->compression_type;
header_bytes[6] = header->compression_level;
BYTES_FROM_UINT64(header_bytes + 7, header->content_size);
if (fwrite(header_bytes, sizeof(header_bytes), 1, output) != 1) {
cc_log("Failed to write common file header");
return false;
}
XXH64_update(checksum, header_bytes, sizeof(header_bytes));
return true;
}
bool common_header_initialize_for_reading(
struct common_header *header,
FILE *input,
const char expected_magic[4],
uint8_t expected_version,
struct decompressor **decompressor,
struct decompr_state **decompr_state,
XXH64_state_t *checksum,
char **errmsg)
{
uint8_t header_bytes[COMMON_HEADER_SIZE];
if (fread(header_bytes, sizeof(header_bytes), 1, input) != 1) {
*errmsg = format("Failed to read common header");
return false;
}
memcpy(header->magic, header_bytes, 4);
header->version = header_bytes[4];
header->compression_type = header_bytes[5];
header->compression_level = header_bytes[6];
header->content_size = UINT64_FROM_BYTES(header_bytes + 7);
if (memcmp(header->magic, expected_magic, sizeof(header->magic)) != 0) {
*errmsg = format(
"Bad magic value 0x%x%x%x%x",
header->magic[0],
header->magic[1],
header->magic[2],
header->magic[3]);
return false;
}
if (header->version != expected_version) {
*errmsg = format(
"Unknown version (actual %u, expected %u)",
header->version,
expected_version);
return false;
}
if (header->compression_type == COMPR_TYPE_NONE) {
// Since we have the size available, let's use it as a super primitive
// consistency check for the non-compressed case. (A real checksum is used
// for compressed data.)
struct stat st;
if (x_fstat(fileno(input), &st) != 0) {
return false;
}
if ((uint64_t)st.st_size != header->content_size) {
*errmsg = format(
"Bad uncompressed file size (actual %llu bytes, expected %llu bytes)",
(unsigned long long)st.st_size,
(unsigned long long)header->content_size);
return false;
}
}
if (!decompressor) {
return true;
}
*decompressor = decompressor_from_type(header->compression_type);
if (!*decompressor) {
*errmsg = format(
"Unknown compression type: %u", header->compression_type);
return false;
}
if (checksum) {
XXH64_reset(checksum, 0);
XXH64_update(checksum, header_bytes, sizeof(header_bytes));
}
*decompr_state = (*decompressor)->init(input, checksum);
if (!*decompr_state) {
*errmsg = x_strdup("Failed to initialize decompressor");
return false;
}
return true;
}
void common_header_dump(const struct common_header *header, FILE *f)
{
fprintf(
f, "Magic: %c%c%c%c\n",
header->magic[0], header->magic[1], header->magic[2], header->magic[3]);
fprintf(f, "Version: %u\n", header->version);
fprintf(f, "Compression type: %s\n",
compression_type_to_string(header->compression_type));
fprintf(f, "Compression level: %d\n", header->compression_level);
fprintf(f, "Content size: %" PRIu64 "\n", header->content_size);
}
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