csum-file.h

   1 #ifndef CSUM_FILE_H
   2 #define CSUM_FILE_H
   3
   4 #include "cache.h"
   5 #include "hash.h"
   6 #include "write-or-die.h"
   7
   8 struct progress;
   9
  10 /* A SHA1-protected file */
  11 struct hashfile {
  12         int fd;
  13         int check_fd;
  14         unsigned int offset;
  15         git_hash_ctx ctx;
  16         off_t total;
  17         struct progress *tp;
  18         const char *name;
  19         int do_crc;
  20         uint32_t crc32;
  21         size_t buffer_len;
  22         unsigned char *buffer;
  23         unsigned char *check_buffer;
  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         git_hash_ctx ctx;
  37 };
  38
  39 void hashfile_checkpoint(struct hashfile *, struct hashfile_checkpoint *);
  40 int hashfile_truncate(struct hashfile *, struct hashfile_checkpoint *);
  41
  42 /* finalize_hashfile flags */
  43 #define CSUM_CLOSE              1
  44 #define CSUM_FSYNC              2
  45 #define CSUM_HASH_IN_STREAM     4
  46
  47 struct hashfile *hashfd(int fd, const char *name);
  48 struct hashfile *hashfd_check(const char *name);
  49 struct hashfile *hashfd_throughput(int fd, const char *name, struct progress *tp);
  50 int finalize_hashfile(struct hashfile *, unsigned char *, enum fsync_component, unsigned int);
  51 void hashwrite(struct hashfile *, const void *, unsigned int);
  52 void hashflush(struct hashfile *f);
  53 void crc32_begin(struct hashfile *);
  54 uint32_t crc32_end(struct hashfile *);
  55
  56 /* Verify checksum validity while reading. Returns non-zero on success. */
  57 int hashfile_checksum_valid(const unsigned char *data, size_t len);
  58
  59 /*
  60  * Returns the total number of bytes fed to the hashfile so far (including ones
  61  * that have not been written out to the descriptor yet).
  62  */
  63 static inline off_t hashfile_total(struct hashfile *f)
  64 {
  65         return f->total + f->offset;
  66 }
  67
  68 static inline void hashwrite_u8(struct hashfile *f, uint8_t data)
  69 {
  70         hashwrite(f, &data, sizeof(data));
  71 }
  72
  73 static inline void hashwrite_be32(struct hashfile *f, uint32_t data)
  74 {
  75         data = htonl(data);
  76         hashwrite(f, &data, sizeof(data));
  77 }
  78
  79 static inline size_t hashwrite_be64(struct hashfile *f, uint64_t data)
  80 {
  81         data = htonll(data);
  82         hashwrite(f, &data, sizeof(data));
  83         return sizeof(data);
  84 }
  85
  86 #endif