mirror of
https://github.com/git/git
synced 2024-11-05 18:59:29 +00:00
019bd34082
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
127 lines
3.5 KiB
C
127 lines
3.5 KiB
C
/*
|
|
Copyright 2020 Google LLC
|
|
|
|
Use of this source code is governed by a BSD-style
|
|
license that can be found in the LICENSE file or at
|
|
https://developers.google.com/open-source/licenses/bsd
|
|
*/
|
|
|
|
#ifndef BLOCK_H
|
|
#define BLOCK_H
|
|
|
|
#include "basics.h"
|
|
#include "record.h"
|
|
#include "reftable-blocksource.h"
|
|
|
|
/*
|
|
* Writes reftable blocks. The block_writer is reused across blocks to minimize
|
|
* allocation overhead.
|
|
*/
|
|
struct block_writer {
|
|
uint8_t *buf;
|
|
uint32_t block_size;
|
|
|
|
/* Offset of the global header. Nonzero in the first block only. */
|
|
uint32_t header_off;
|
|
|
|
/* How often to restart keys. */
|
|
int restart_interval;
|
|
int hash_size;
|
|
|
|
/* Offset of next uint8_t to write. */
|
|
uint32_t next;
|
|
uint32_t *restarts;
|
|
uint32_t restart_len;
|
|
uint32_t restart_cap;
|
|
|
|
struct strbuf last_key;
|
|
int entries;
|
|
};
|
|
|
|
/*
|
|
* initializes the blockwriter to write `typ` entries, using `buf` as temporary
|
|
* storage. `buf` is not owned by the block_writer. */
|
|
void block_writer_init(struct block_writer *bw, uint8_t typ, uint8_t *buf,
|
|
uint32_t block_size, uint32_t header_off, int hash_size);
|
|
|
|
/* returns the block type (eg. 'r' for ref records. */
|
|
uint8_t block_writer_type(struct block_writer *bw);
|
|
|
|
/* appends the record, or -1 if it doesn't fit. */
|
|
int block_writer_add(struct block_writer *w, struct reftable_record *rec);
|
|
|
|
/* appends the key restarts, and compress the block if necessary. */
|
|
int block_writer_finish(struct block_writer *w);
|
|
|
|
/* clears out internally allocated block_writer members. */
|
|
void block_writer_release(struct block_writer *bw);
|
|
|
|
/* Read a block. */
|
|
struct block_reader {
|
|
/* offset of the block header; nonzero for the first block in a
|
|
* reftable. */
|
|
uint32_t header_off;
|
|
|
|
/* the memory block */
|
|
struct reftable_block block;
|
|
int hash_size;
|
|
|
|
/* size of the data, excluding restart data. */
|
|
uint32_t block_len;
|
|
uint8_t *restart_bytes;
|
|
uint16_t restart_count;
|
|
|
|
/* size of the data in the file. For log blocks, this is the compressed
|
|
* size. */
|
|
uint32_t full_block_size;
|
|
};
|
|
|
|
/* Iterate over entries in a block */
|
|
struct block_iter {
|
|
/* offset within the block of the next entry to read. */
|
|
uint32_t next_off;
|
|
struct block_reader *br;
|
|
|
|
/* key for last entry we read. */
|
|
struct strbuf last_key;
|
|
};
|
|
|
|
/* initializes a block reader. */
|
|
int block_reader_init(struct block_reader *br, struct reftable_block *bl,
|
|
uint32_t header_off, uint32_t table_block_size,
|
|
int hash_size);
|
|
|
|
/* Position `it` at start of the block */
|
|
void block_reader_start(struct block_reader *br, struct block_iter *it);
|
|
|
|
/* Position `it` to the `want` key in the block */
|
|
int block_reader_seek(struct block_reader *br, struct block_iter *it,
|
|
struct strbuf *want);
|
|
|
|
/* Returns the block type (eg. 'r' for refs) */
|
|
uint8_t block_reader_type(struct block_reader *r);
|
|
|
|
/* Decodes the first key in the block */
|
|
int block_reader_first_key(struct block_reader *br, struct strbuf *key);
|
|
|
|
void block_iter_copy_from(struct block_iter *dest, struct block_iter *src);
|
|
|
|
/* return < 0 for error, 0 for OK, > 0 for EOF. */
|
|
int block_iter_next(struct block_iter *it, struct reftable_record *rec);
|
|
|
|
/* Seek to `want` with in the block pointed to by `it` */
|
|
int block_iter_seek(struct block_iter *it, struct strbuf *want);
|
|
|
|
/* deallocate memory for `it`. The block reader and its block is left intact. */
|
|
void block_iter_close(struct block_iter *it);
|
|
|
|
/* size of file header, depending on format version */
|
|
int header_size(int version);
|
|
|
|
/* size of file footer, depending on format version */
|
|
int footer_size(int version);
|
|
|
|
/* returns a block to its source. */
|
|
void reftable_block_done(struct reftable_block *ret);
|
|
|
|
#endif
|