Adding upstream version 1:2.39.2.upstream/1%2.39.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 232 insertions, 0 deletions

diff --git a/csum-file.c b/csum-file.c
new file mode 100644
index 0000000..59ef339
--- /dev/null
+++ b/csum-file.c
@@ -0,0 +1,232 @@
+/*
+ * 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 verify_buffer_or_die(struct hashfile *f,
+				 const void *buf,
+				 unsigned int count)
+{
+	ssize_t ret = read_in_full(f->check_fd, f->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, f->check_buffer, count))
+		die("sha1 file '%s' validation error", f->name);
+}
+
+static void flush(struct hashfile *f, const void *buf, unsigned int count)
+{
+	if (0 <= f->check_fd && count)
+		verify_buffer_or_die(f, buf, count);
+
+	if (write_in_full(f->fd, buf, count) < 0) {
+		if (errno == ENOSPC)
+			die("sha1 file '%s' write error. Out of diskspace", f->name);
+		die_errno("sha1 file '%s' write error", f->name);
+	}
+
+	f->total += count;
+	display_throughput(f->tp, f->total);
+}
+
+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;
+	}
+}
+
+static void free_hashfile(struct hashfile *f)
+{
+	free(f->buffer);
+	free(f->check_buffer);
+	free(f);
+}
+
+int finalize_hashfile(struct hashfile *f, unsigned char *result,
+		      enum fsync_component component, 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_component_or_die(component, 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_hashfile(f);
+	return fd;
+}
+
+void hashwrite(struct hashfile *f, const void *buf, unsigned int count)
+{
+	while (count) {
+		unsigned left = f->buffer_len - f->offset;
+		unsigned nr = count > left ? left : count;
+
+		if (f->do_crc)
+			f->crc32 = crc32(f->crc32, buf, nr);
+
+		if (nr == f->buffer_len) {
+			/*
+			 * Flush a full batch worth of data directly
+			 * from the input, skipping the memcpy() to
+			 * the hashfile's buffer. In this block,
+			 * f->offset is necessarily zero.
+			 */
+			the_hash_algo->update_fn(&f->ctx, buf, nr);
+			flush(f, buf, nr);
+		} else {
+			/*
+			 * Copy to the hashfile's buffer, flushing only
+			 * if it became full.
+			 */
+			memcpy(f->buffer + f->offset, buf, nr);
+			f->offset += nr;
+			left -= nr;
+			if (!left)
+				hashflush(f);
+		}
+
+		count -= nr;
+		buf = (char *) buf + nr;
+	}
+}
+
+struct hashfile *hashfd_check(const char *name)
+{
+	int sink, check;
+	struct hashfile *f;
+
+	sink = xopen("/dev/null", O_WRONLY);
+	check = xopen(name, O_RDONLY);
+	f = hashfd(sink, name);
+	f->check_fd = check;
+	f->check_buffer = xmalloc(f->buffer_len);
+
+	return f;
+}
+
+static struct hashfile *hashfd_internal(int fd, const char *name,
+					struct progress *tp,
+					size_t buffer_len)
+{
+	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);
+
+	f->buffer_len = buffer_len;
+	f->buffer = xmalloc(buffer_len);
+	f->check_buffer = NULL;
+
+	return f;
+}
+
+struct hashfile *hashfd(int fd, const char *name)
+{
+	/*
+	 * Since we are not going to use a progress meter to
+	 * measure the rate of data passing through this hashfile,
+	 * use a larger buffer size to reduce fsync() calls.
+	 */
+	return hashfd_internal(fd, name, NULL, 128 * 1024);
+}
+
+struct hashfile *hashfd_throughput(int fd, const char *name, struct progress *tp)
+{
+	/*
+	 * Since we are expecting to report progress of the
+	 * write into this hashfile, use a smaller buffer
+	 * size so the progress indicators arrive at a more
+	 * frequent rate.
+	 */
+	return hashfd_internal(fd, name, tp, 8 * 1024);
+}
+
+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;
+}
+
+int hashfile_checksum_valid(const unsigned char *data, size_t total_len)
+{
+	unsigned char got[GIT_MAX_RAWSZ];
+	git_hash_ctx ctx;
+	size_t data_len = total_len - the_hash_algo->rawsz;
+
+	if (total_len < the_hash_algo->rawsz)
+		return 0; /* say "too short"? */
+
+	the_hash_algo->init_fn(&ctx);
+	the_hash_algo->update_fn(&ctx, data, data_len);
+	the_hash_algo->final_fn(got, &ctx);
+
+	return hasheq(got, data + data_len);
+}