git/csum-file.h
Neeraj Singh 020406eaa5 core.fsync: introduce granular fsync control infrastructure
This commit introduces the infrastructure for the core.fsync
configuration knob. The repository components we want to sync
are identified by flags so that we can turn on or off syncing
for specific components.

If core.fsyncObjectFiles is set and the core.fsync configuration
also includes FSYNC_COMPONENT_LOOSE_OBJECT, we will fsync any
loose objects. This picks the strictest data integrity behavior
if core.fsync and core.fsyncObjectFiles are set to conflicting values.

This change introduces the currently unused fsync_component
helper, which will be used by a later patch that adds fsyncing to
the refs backend.

Actual configuration and documentation of the fsync components
list are in other patches in the series to separate review of
the underlying mechanism from the policy of how it's configured.

Helped-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-10 15:10:22 -08:00

79 lines
1.9 KiB
C

#ifndef CSUM_FILE_H
#define CSUM_FILE_H
#include "cache.h"
#include "hash.h"
struct progress;
/* A SHA1-protected file */
struct hashfile {
int fd;
int check_fd;
unsigned int offset;
git_hash_ctx ctx;
off_t total;
struct progress *tp;
const char *name;
int do_crc;
uint32_t crc32;
size_t buffer_len;
unsigned char *buffer;
unsigned char *check_buffer;
};
/* Checkpoint */
struct hashfile_checkpoint {
off_t offset;
git_hash_ctx ctx;
};
void hashfile_checkpoint(struct hashfile *, struct hashfile_checkpoint *);
int hashfile_truncate(struct hashfile *, struct hashfile_checkpoint *);
/* finalize_hashfile flags */
#define CSUM_CLOSE 1
#define CSUM_FSYNC 2
#define CSUM_HASH_IN_STREAM 4
struct hashfile *hashfd(int fd, const char *name);
struct hashfile *hashfd_check(const char *name);
struct hashfile *hashfd_throughput(int fd, const char *name, struct progress *tp);
int finalize_hashfile(struct hashfile *, unsigned char *, enum fsync_component, unsigned int);
void hashwrite(struct hashfile *, const void *, unsigned int);
void hashflush(struct hashfile *f);
void crc32_begin(struct hashfile *);
uint32_t crc32_end(struct hashfile *);
/* Verify checksum validity while reading. Returns non-zero on success. */
int hashfile_checksum_valid(const unsigned char *data, size_t len);
/*
* Returns the total number of bytes fed to the hashfile so far (including ones
* that have not been written out to the descriptor yet).
*/
static inline off_t hashfile_total(struct hashfile *f)
{
return f->total + f->offset;
}
static inline void hashwrite_u8(struct hashfile *f, uint8_t data)
{
hashwrite(f, &data, sizeof(data));
}
static inline void hashwrite_be32(struct hashfile *f, uint32_t data)
{
data = htonl(data);
hashwrite(f, &data, sizeof(data));
}
static inline size_t hashwrite_be64(struct hashfile *f, uint64_t data)
{
data = htonll(data);
hashwrite(f, &data, sizeof(data));
return sizeof(data);
}
#endif