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1 #ifndef CSUM_FILE_H
2 #define CSUM_FILE_H
3
4 #include "hash.h"
5 #include "write-or-die.h"
6
7 struct progress;
8
9 /* A SHA1-protected file */
10 struct hashfile {
11 int fd;
12 int check_fd;
13 unsigned int offset;
14 struct git_hash_ctx ctx;
15 off_t total;
16 struct progress *tp;
17 const char *name;
18 int do_crc;
19 uint32_t crc32;
20 size_t buffer_len;
21 unsigned char *buffer;
22 unsigned char *check_buffer;
23 const struct git_hash_algo *algop;
24
25 /**
26 * If non-zero, skip_hash indicates that we should
27 * not actually compute the hash for this hashfile and
28 * instead only use it as a buffered write.
29 */
30 int skip_hash;
31 };
32
33 /* Checkpoint */
34 struct hashfile_checkpoint {
35 off_t offset;
36 struct git_hash_ctx ctx;
37 };
38
39 void hashfile_checkpoint_init(struct hashfile *, struct hashfile_checkpoint *);
40 void hashfile_checkpoint(struct hashfile *, struct hashfile_checkpoint *);
41 int hashfile_truncate(struct hashfile *, struct hashfile_checkpoint *);
42 void hashfile_checkpoint_release(struct hashfile_checkpoint *);
43
44 /* finalize_hashfile flags */
45 #define CSUM_CLOSE 1
46 #define CSUM_FSYNC 2
47 #define CSUM_HASH_IN_STREAM 4
48
49 struct hashfd_options {
50 /*
51 * Throughput progress that counts the number of bytes that have been
52 * hashed.
53 */
54 struct progress *progress;
55
56 /* The length of the buffer that shall be used to read data. */
57 size_t buffer_len;
58 };
59
60 struct hashfile *hashfd_ext(const struct git_hash_algo *algop,
61 int fd, const char *name,
62 const struct hashfd_options *opts);
63 struct hashfile *hashfd(const struct git_hash_algo *algop,
64 int fd, const char *name);
65 struct hashfile *hashfd_check(const struct git_hash_algo *algop,
66 const char *name);
67
68 /*
69 * Free the hashfile without flushing its contents to disk. This only
70 * needs to be called when not calling `finalize_hashfile()`.
71 */
72 void free_hashfile(struct hashfile *f);
73
74 /*
75 * Finalize the hashfile by flushing data to disk and free'ing it.
76 */
77 int finalize_hashfile(struct hashfile *, unsigned char *, enum fsync_component, unsigned int);
78 void hashwrite(struct hashfile *, const void *, uint32_t);
79 void hashflush(struct hashfile *f);
80 void crc32_begin(struct hashfile *);
81 uint32_t crc32_end(struct hashfile *);
82
83 /* Verify checksum validity while reading. Returns non-zero on success. */
84 int hashfile_checksum_valid(const struct git_hash_algo *algop,
85 const unsigned char *data, size_t len);
86
87 /*
88 * Returns the total number of bytes fed to the hashfile so far (including ones
89 * that have not been written out to the descriptor yet).
90 */
91 static inline off_t hashfile_total(struct hashfile *f)
92 {
93 return f->total + f->offset;
94 }
95
96 static inline void hashwrite_u8(struct hashfile *f, uint8_t data)
97 {
98 hashwrite(f, &data, sizeof(data));
99 }
100
101 static inline void hashwrite_be32(struct hashfile *f, uint32_t data)
102 {
103 data = htonl(data);
104 hashwrite(f, &data, sizeof(data));
105 }
106
107 static inline size_t hashwrite_be64(struct hashfile *f, uint64_t data)
108 {
109 data = htonll(data);
110 hashwrite(f, &data, sizeof(data));
111 return sizeof(data);
112 }
113
114 #endif