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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 09:49:36 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 09:49:36 +0000
commit5ec6074f0633939fd17d94111d10c6c6b062978c (patch)
treebfaa17b5a64abc66c918e9c70969e519d9e1df8e /csum-file.c
parentInitial commit. (diff)
downloadgit-5ec6074f0633939fd17d94111d10c6c6b062978c.tar.xz
git-5ec6074f0633939fd17d94111d10c6c6b062978c.zip
Adding upstream version 1:2.30.2.upstream/1%2.30.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'csum-file.c')
-rw-r--r--csum-file.c186
1 files changed, 186 insertions, 0 deletions
diff --git a/csum-file.c b/csum-file.c
new file mode 100644
index 0000000..0f35fa5
--- /dev/null
+++ b/csum-file.c
@@ -0,0 +1,186 @@
+/*
+ * 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 hashfile *f, const void *buf, unsigned int count)
+{
+ if (0 <= f->check_fd && count) {
+ unsigned char check_buffer[8192];
+ ssize_t ret = read_in_full(f->check_fd, check_buffer, count);
+
+ if (ret < 0)
+ die_errno("%s: sha1 file read error", f->name);
+ if (ret != count)
+ die("%s: sha1 file truncated", f->name);
+ if (memcmp(buf, check_buffer, count))
+ die("sha1 file '%s' validation error", f->name);
+ }
+
+ 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 hashflush(struct hashfile *f)
+{
+ unsigned offset = f->offset;
+
+ if (offset) {
+ the_hash_algo->update_fn(&f->ctx, f->buffer, offset);
+ flush(f, f->buffer, offset);
+ f->offset = 0;
+ }
+}
+
+int finalize_hashfile(struct hashfile *f, unsigned char *result, unsigned int flags)
+{
+ int fd;
+
+ hashflush(f);
+ the_hash_algo->final_fn(f->buffer, &f->ctx);
+ if (result)
+ hashcpy(result, f->buffer);
+ if (flags & CSUM_HASH_IN_STREAM)
+ flush(f, f->buffer, the_hash_algo->rawsz);
+ if (flags & CSUM_FSYNC)
+ fsync_or_die(f->fd, f->name);
+ if (flags & CSUM_CLOSE) {
+ if (close(f->fd))
+ die_errno("%s: sha1 file error on close", f->name);
+ fd = 0;
+ } else
+ fd = f->fd;
+ if (0 <= f->check_fd) {
+ char discard;
+ int cnt = read_in_full(f->check_fd, &discard, 1);
+ if (cnt < 0)
+ die_errno("%s: error when reading the tail of sha1 file",
+ f->name);
+ if (cnt)
+ die("%s: sha1 file has trailing garbage", f->name);
+ if (close(f->check_fd))
+ die_errno("%s: sha1 file error on close", f->name);
+ }
+ free(f);
+ return fd;
+}
+
+void hashwrite(struct hashfile *f, const void *buf, unsigned int count)
+{
+ while (count) {
+ unsigned offset = f->offset;
+ unsigned left = sizeof(f->buffer) - offset;
+ unsigned nr = count > left ? left : count;
+ const 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) {
+ the_hash_algo->update_fn(&f->ctx, data, offset);
+ flush(f, data, offset);
+ offset = 0;
+ }
+ f->offset = offset;
+ }
+}
+
+struct hashfile *hashfd(int fd, const char *name)
+{
+ return hashfd_throughput(fd, name, NULL);
+}
+
+struct hashfile *hashfd_check(const char *name)
+{
+ int sink, check;
+ struct hashfile *f;
+
+ sink = open("/dev/null", O_WRONLY);
+ if (sink < 0)
+ die_errno("unable to open /dev/null");
+ check = open(name, O_RDONLY);
+ if (check < 0)
+ die_errno("unable to open '%s'", name);
+ f = hashfd(sink, name);
+ f->check_fd = check;
+ return f;
+}
+
+struct hashfile *hashfd_throughput(int fd, const char *name, struct progress *tp)
+{
+ struct hashfile *f = xmalloc(sizeof(*f));
+ f->fd = fd;
+ f->check_fd = -1;
+ f->offset = 0;
+ f->total = 0;
+ f->tp = tp;
+ f->name = name;
+ f->do_crc = 0;
+ the_hash_algo->init_fn(&f->ctx);
+ return f;
+}
+
+void hashfile_checkpoint(struct hashfile *f, struct hashfile_checkpoint *checkpoint)
+{
+ hashflush(f);
+ checkpoint->offset = f->total;
+ the_hash_algo->clone_fn(&checkpoint->ctx, &f->ctx);
+}
+
+int hashfile_truncate(struct hashfile *f, struct hashfile_checkpoint *checkpoint)
+{
+ off_t offset = checkpoint->offset;
+
+ if (ftruncate(f->fd, offset) ||
+ lseek(f->fd, offset, SEEK_SET) != offset)
+ return -1;
+ f->total = offset;
+ f->ctx = checkpoint->ctx;
+ f->offset = 0; /* hashflush() was called in checkpoint */
+ return 0;
+}
+
+void crc32_begin(struct hashfile *f)
+{
+ f->crc32 = crc32(0, NULL, 0);
+ f->do_crc = 1;
+}
+
+uint32_t crc32_end(struct hashfile *f)
+{
+ f->do_crc = 0;
+ return f->crc32;
+}