From: Aki Tuomi <aki.tuomi@open-xchange.com>
Date: Sat, 8 Feb 2020 19:56:21 +0000 (+0200)
Subject: lib: ostream - Add o_stream_create_file
X-Git-Tag: 2.3.11.2~596
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b2dca5344fbc9c334238362e0785a6168f07ac49;p=thirdparty%2Fdovecot%2Fcore.git

lib: ostream - Add o_stream_create_file

Opens file for reading, and creates it, if it exists.
---

diff --git a/src/lib/ostream-file.c b/src/lib/ostream-file.c
index e3a85e2b4f..869a670ddc 100644
--- a/src/lib/ostream-file.c
+++ b/src/lib/ostream-file.c
@@ -16,6 +16,7 @@
 #ifdef HAVE_SYS_UIO_H
 #  include <sys/uio.h>
 #endif
+#include <fcntl.h>
 
 /* try to keep the buffer size within 4k..128k. ReiserFS may actually return
    128k as optimal size. */
@@ -1117,3 +1118,17 @@ struct ostream *o_stream_create_fd_file_autoclose(int *fd, uoff_t offset)
 	*fd = -1;
 	return output;
 }
+
+struct ostream *o_stream_create_file(const char *path, uoff_t offset, mode_t mode,
+				     enum ostream_create_file_flags flags)
+{
+	int fd;
+	int open_flags = O_WRONLY|O_CREAT;
+	if (HAS_ANY_BITS(flags, OSTREAM_CREATE_FILE_FLAG_APPEND))
+		open_flags |= O_APPEND;
+	else
+		open_flags |= O_TRUNC;
+	if ((fd = open(path, open_flags, mode)) < 0)
+		return o_stream_create_error(errno);
+	return o_stream_create_fd_file_autoclose(&fd, offset);
+}
diff --git a/src/lib/ostream.h b/src/lib/ostream.h
index 25a09cc55e..277cbe1503 100644
--- a/src/lib/ostream.h
+++ b/src/lib/ostream.h
@@ -17,6 +17,11 @@ enum ostream_send_istream_result {
 	OSTREAM_SEND_ISTREAM_RESULT_ERROR_OUTPUT
 };
 
+enum ostream_create_file_flags {
+  /* without append, file is truncated */
+  OSTREAM_CREATE_FILE_FLAG_APPEND = BIT(0),
+};
+
 struct ostream {
 	/* Number of bytes sent via o_stream_send*() and similar functions.
 	   This is counting the input data. For example with a compressed
@@ -59,6 +64,9 @@ struct ostream *o_stream_create_fd_autoclose(int *fd, size_t max_buffer_size);
 struct ostream *
 o_stream_create_fd_file(int fd, uoff_t offset, bool autoclose_fd);
 struct ostream *o_stream_create_fd_file_autoclose(int *fd, uoff_t offset);
+/* Create ostream for file. If append flag is not set, file will be truncated. */
+struct ostream *o_stream_create_file(const char *path, uoff_t offset, mode_t mode,
+				     enum ostream_create_file_flags flags);
 /* Create an output stream to a buffer. */
 struct ostream *o_stream_create_buffer(buffer_t *buf);
 /* Create an output streams that always fails the writes. */