50 lines
1.4 KiB
C
50 lines
1.4 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 REFTABLE_BLOCKSOURCE_H
|
||
|
|
#define REFTABLE_BLOCKSOURCE_H
|
||
|
|
|
||
|
|
#include <stdint.h>
|
||
|
|
|
||
|
|
/* block_source is a generic wrapper for a seekable readable file.
|
||
|
|
*/
|
||
|
|
struct reftable_block_source {
|
||
|
|
struct reftable_block_source_vtable *ops;
|
||
|
|
void *arg;
|
||
|
|
};
|
||
|
|
|
||
|
|
/* a contiguous segment of bytes. It keeps track of its generating block_source
|
||
|
|
* so it can return itself into the pool. */
|
||
|
|
struct reftable_block {
|
||
|
|
uint8_t *data;
|
||
|
|
int len;
|
||
|
|
struct reftable_block_source source;
|
||
|
|
};
|
||
|
|
|
||
|
|
/* block_source_vtable are the operations that make up block_source */
|
||
|
|
struct reftable_block_source_vtable {
|
||
|
|
/* returns the size of a block source */
|
||
|
|
uint64_t (*size)(void *source);
|
||
|
|
|
||
|
|
/* reads a segment from the block source. It is an error to read
|
||
|
|
beyond the end of the block */
|
||
|
|
int (*read_block)(void *source, struct reftable_block *dest,
|
||
|
|
uint64_t off, uint32_t size);
|
||
|
|
/* mark the block as read; may return the data back to malloc */
|
||
|
|
void (*return_block)(void *source, struct reftable_block *blockp);
|
||
|
|
|
||
|
|
/* release all resources associated with the block source */
|
||
|
|
void (*close)(void *source);
|
||
|
|
};
|
||
|
|
|
||
|
|
/* opens a file on the file system as a block_source */
|
||
|
|
int reftable_block_source_from_file(struct reftable_block_source *block_src,
|
||
|
|
const char *name);
|
||
|
|
|
||
|
|
#endif
|