Files
git/reftable/reader.h
Patrick Steinhardt 7c4c1cbc0b reftable/blocksource: adjust read_block() to return ssize_t
The `block_source_read_block()` function and its implementations return
an integer as a result that reflects either the number of bytes read, or
an error. As such its return type, a signed integer, isn't wrong, but it
doesn't give the reader a good hint what it actually returns.

Refactor the function to return an `ssize_t` instead, which is typical
for functions similar to read(3p) and should thus give readers a better
signal what they can expect as a result.

Adjust callers to better handle the returned value to avoid warnings
with -Wsign-compare. One of these callers is `reader_get_block()`, whose
return value is only ever used by its callers to figure out whether or
not the read was successful. So instead of bubbling up the `ssize_t`
there, too, we adapt it to only indicate success or errors.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-21 14:20:30 -08:00

68 lines
1.7 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 READER_H
#define READER_H
#include "block.h"
#include "record.h"
#include "reftable-iterator.h"
#include "reftable-reader.h"
uint64_t block_source_size(struct reftable_block_source *source);
ssize_t block_source_read_block(struct reftable_block_source *source,
struct reftable_block *dest, uint64_t off,
uint32_t size);
void block_source_close(struct reftable_block_source *source);
/* metadata for a block type */
struct reftable_reader_offsets {
int is_present;
uint64_t offset;
uint64_t index_offset;
};
/* The state for reading a reftable file. */
struct reftable_reader {
/* for convenience, associate a name with the instance. */
char *name;
struct reftable_block_source source;
/* Size of the file, excluding the footer. */
uint64_t size;
/* The hash function used for ref records. */
enum reftable_hash hash_id;
uint32_t block_size;
uint64_t min_update_index;
uint64_t max_update_index;
/* Length of the OID keys in the 'o' section */
int object_id_len;
int version;
struct reftable_reader_offsets ref_offsets;
struct reftable_reader_offsets obj_offsets;
struct reftable_reader_offsets log_offsets;
uint64_t refcount;
};
const char *reader_name(struct reftable_reader *r);
int reader_init_iter(struct reftable_reader *r,
struct reftable_iterator *it,
uint8_t typ);
/* initialize a block reader to read from `r` */
int reader_init_block_reader(struct reftable_reader *r, struct block_reader *br,
uint64_t next_off, uint8_t want_typ);
#endif