1 /* 2 * Copyright (c) 2012-2013 Spotify AB 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not 5 * use this file except in compliance with the License. You may obtain a copy of 6 * the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 13 * License for the specific language governing permissions and limitations under 14 * the License. 15 */ 16 #ifndef SPARKEY_LOGHEADER_H_INCLUDED 17 #define SPARKEY_LOGHEADER_H_INCLUDED 18 19 #include <stdint.h> 20 21 #include "sparkey.h" 22 23 #define LOG_MAGIC_NUMBER (0x49b39c95) 24 #define LOG_MAJOR_VERSION (1) 25 #define LOG_MINOR_VERSION (0) 26 #define LOG_HEADER_SIZE (84) 27 28 typedef struct { 29 uint32_t major_version; 30 uint32_t minor_version; 31 uint32_t file_identifier; 32 uint64_t num_puts; 33 uint64_t num_deletes; 34 uint64_t data_end; 35 uint64_t max_key_len; 36 uint64_t max_value_len; 37 uint64_t delete_size; 38 sparkey_compression_type compression_type; 39 uint32_t compression_block_size; 40 uint64_t put_size; 41 uint32_t header_size; 42 uint32_t max_entries_per_block; 43 } sparkey_logheader; 44 45 /** 46 * fills up a logheader struct based on the contents at the beginning of the file. 47 * @param header header struct to fill 48 * @param filename a log file 49 * @returns an error code if it could not load the file. 50 */ 51 sparkey_returncode sparkey_load_logheader(sparkey_logheader *header, const char *filename); 52 53 /** 54 * Dumps a human readable representation of the header to stdout 55 * @param header an initialized header struct 56 */ 57 void print_logheader(sparkey_logheader *header); 58 59 /** 60 * Writes a header to the current position in the file 61 * @param fd a file descripter pointing to a file open for writing 62 * @param header the header to write 63 * @returns an error code if it could not write to file. 64 */ 65 sparkey_returncode write_logheader(int fd, sparkey_logheader *header); 66 67 #endif 68 69