Squashed 'third_party/git/' content from commit cb71568594

git-subtree-dir: third_party/git
git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7

copy.c

@@ -0,0 +1,67 @@
+#include "cache.h"
+
+int copy_fd(int ifd, int ofd)
+{
+	while (1) {
+		char buffer[8192];
+		ssize_t len = xread(ifd, buffer, sizeof(buffer));
+		if (!len)
+			break;
+		if (len < 0)
+			return COPY_READ_ERROR;
+		if (write_in_full(ofd, buffer, len) < 0)
+			return COPY_WRITE_ERROR;
+	}
+	return 0;
+}
+
+static int copy_times(const char *dst, const char *src)
+{
+	struct stat st;
+	struct utimbuf times;
+	if (stat(src, &st) < 0)
+		return -1;
+	times.actime = st.st_atime;
+	times.modtime = st.st_mtime;
+	if (utime(dst, &times) < 0)
+		return -1;
+	return 0;
+}
+
+int copy_file(const char *dst, const char *src, int mode)
+{
+	int fdi, fdo, status;
+
+	mode = (mode & 0111) ? 0777 : 0666;
+	if ((fdi = open(src, O_RDONLY)) < 0)
+		return fdi;
+	if ((fdo = open(dst, O_WRONLY | O_CREAT | O_EXCL, mode)) < 0) {
+		close(fdi);
+		return fdo;
+	}
+	status = copy_fd(fdi, fdo);
+	switch (status) {
+	case COPY_READ_ERROR:
+		error_errno("copy-fd: read returned");
+		break;
+	case COPY_WRITE_ERROR:
+		error_errno("copy-fd: write returned");
+		break;
+	}
+	close(fdi);
+	if (close(fdo) != 0)
+		return error_errno("%s: close error", dst);
+
+	if (!status && adjust_shared_perm(dst))
+		return -1;
+
+	return status;
+}
+
+int copy_file_with_time(const char *dst, const char *src, int mode)
+{
+	int status = copy_file(dst, src, mode);
+	if (!status)
+		return copy_times(dst, src);
+	return status;
+}