| /* |
| * csum-file.c |
| * |
| * Copyright (C) 2005 Linus Torvalds |
| * |
| * Simple file write infrastructure for writing SHA1-summed |
| * files. Useful when you write a file that you want to be |
| * able to verify hasn't been messed with afterwards. |
| */ |
| #include "cache.h" |
| #include "progress.h" |
| #include "csum-file.h" |
| |
| static void flush(struct sha1file *f, void * buf, unsigned int count) |
| { |
| for (;;) { |
| int ret = xwrite(f->fd, buf, count); |
| if (ret > 0) { |
| f->total += ret; |
| display_throughput(f->tp, f->total); |
| buf = (char *) buf + ret; |
| count -= ret; |
| if (count) |
| continue; |
| return; |
| } |
| if (!ret) |
| die("sha1 file '%s' write error. Out of diskspace", f->name); |
| die_errno("sha1 file '%s' write error", f->name); |
| } |
| } |
| |
| void sha1flush(struct sha1file *f) |
| { |
| unsigned offset = f->offset; |
| |
| if (offset) { |
| git_SHA1_Update(&f->ctx, f->buffer, offset); |
| flush(f, f->buffer, offset); |
| f->offset = 0; |
| } |
| } |
| |
| int sha1close(struct sha1file *f, unsigned char *result, unsigned int flags) |
| { |
| int fd; |
| |
| sha1flush(f); |
| git_SHA1_Final(f->buffer, &f->ctx); |
| if (result) |
| hashcpy(result, f->buffer); |
| if (flags & (CSUM_CLOSE | CSUM_FSYNC)) { |
| /* write checksum and close fd */ |
| flush(f, f->buffer, 20); |
| if (flags & CSUM_FSYNC) |
| fsync_or_die(f->fd, f->name); |
| if (close(f->fd)) |
| die_errno("%s: sha1 file error on close", f->name); |
| fd = 0; |
| } else |
| fd = f->fd; |
| free(f); |
| return fd; |
| } |
| |
| int sha1write(struct sha1file *f, void *buf, unsigned int count) |
| { |
| while (count) { |
| unsigned offset = f->offset; |
| unsigned left = sizeof(f->buffer) - offset; |
| unsigned nr = count > left ? left : count; |
| void *data; |
| |
| if (f->do_crc) |
| f->crc32 = crc32(f->crc32, buf, nr); |
| |
| if (nr == sizeof(f->buffer)) { |
| /* process full buffer directly without copy */ |
| data = buf; |
| } else { |
| memcpy(f->buffer + offset, buf, nr); |
| data = f->buffer; |
| } |
| |
| count -= nr; |
| offset += nr; |
| buf = (char *) buf + nr; |
| left -= nr; |
| if (!left) { |
| git_SHA1_Update(&f->ctx, data, offset); |
| flush(f, data, offset); |
| offset = 0; |
| } |
| f->offset = offset; |
| } |
| return 0; |
| } |
| |
| struct sha1file *sha1fd(int fd, const char *name) |
| { |
| return sha1fd_throughput(fd, name, NULL); |
| } |
| |
| struct sha1file *sha1fd_throughput(int fd, const char *name, struct progress *tp) |
| { |
| struct sha1file *f = xmalloc(sizeof(*f)); |
| f->fd = fd; |
| f->offset = 0; |
| f->total = 0; |
| f->tp = tp; |
| f->name = name; |
| f->do_crc = 0; |
| git_SHA1_Init(&f->ctx); |
| return f; |
| } |
| |
| void crc32_begin(struct sha1file *f) |
| { |
| f->crc32 = crc32(0, NULL, 0); |
| f->do_crc = 1; |
| } |
| |
| uint32_t crc32_end(struct sha1file *f) |
| { |
| f->do_crc = 0; |
| return f->crc32; |
| } |