[v8,02/20] trace-cmd library: Internal helpers for compressing data

Commit Message

Tzvetomir Stoyanov (VMware) Jan. 26, 2022, 9:48 a.m. UTC

New library internal helper functions are introduced, to add compression
functionality to the output trace handler.

Signed-off-by: Tzvetomir Stoyanov (VMware) <[e-mail]>
---
 lib/trace-cmd/include/trace-cmd-local.h |  7 +++
 lib/trace-cmd/trace-output.c            | 65 +++++++++++++++++++++++--
 2 files changed, 69 insertions(+), 3 deletions(-)

Patch

diff --git a/lib/trace-cmd/include/trace-cmd-local.h b/lib/trace-cmd/include/trace-cmd-local.h
index d4047429..b848514e 100644
--- a/lib/trace-cmd/include/trace-cmd-local.h
+++ b/lib/trace-cmd/include/trace-cmd-local.h
@@ -42,6 +42,13 @@  void tracecmd_compress_free(void);
 bool check_file_state(unsigned long file_version, int current_state, int new_state);
 bool check_out_state(struct tracecmd_output *handle, int new_state);
 
+int out_uncompress_block(struct tracecmd_output *handle);
+int out_compression_start(struct tracecmd_output *handle, bool compress);
+int out_compression_end(struct tracecmd_output *handle, bool compress);
+void out_compression_reset(struct tracecmd_output *handle, bool compress);
+unsigned long long out_copy_fd_compress(struct tracecmd_output *handle,
+					int fd, unsigned long long max,
+					unsigned long long *write_size);
 unsigned long long
 out_write_section_header(struct tracecmd_output *handle, unsigned short header_id,
 			 char *description, int flags, bool option);
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index 15baef8f..87481e33 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -70,6 +70,8 @@  struct tracecmd_output {
 
 	unsigned long long	options_start;
 	bool			big_endian;
+	bool			do_compress;
+	struct tracecmd_compression *compress;
 
 	struct list_head	options;
 	struct list_head	buffers;
@@ -100,6 +102,9 @@  static int save_string_section(struct tracecmd_output *handle);
 static stsize_t
 do_write_check(struct tracecmd_output *handle, const void *data, tsize_t size)
 {
+	if (handle->do_compress)
+		return tracecmd_compress_buffer_write(handle->compress, data, size);
+
 	if (handle->msg_handle)
 		return tracecmd_msg_data_send(handle->msg_handle, data, size);
 
@@ -108,10 +113,21 @@  do_write_check(struct tracecmd_output *handle, const void *data, tsize_t size)
 
 static inline off64_t do_lseek(struct tracecmd_output *handle, off_t offset, int whence)
 {
+	if (handle->do_compress)
+		return tracecmd_compress_lseek(handle->compress, offset, whence);
+
 	if (handle->msg_handle)
 		return msg_lseek(handle->msg_handle, offset, whence);
-	else
-		return lseek64(handle->fd, offset, whence);
+
+	return lseek64(handle->fd, offset, whence);
+}
+
+static inline int do_preed(struct tracecmd_output *handle, void *dst, int len, off_t offset)
+{
+	if (handle->do_compress)
+		return tracecmd_compress_pread(handle->compress, dst, len, offset);
+
+	return pread(handle->fd, dst, len, offset);
 }
 
 static short convert_endian_2(struct tracecmd_output *handle, short val)
@@ -139,6 +155,49 @@  static unsigned long long convert_endian_8(struct tracecmd_output *handle,
 	return tep_read_number(handle->pevent, &val, 8);
 }
 
+__hidden void out_compression_reset(struct tracecmd_output *handle, bool compress)
+{
+	if (!compress || !handle->compress)
+		return;
+
+	tracecmd_compress_reset(handle->compress);
+	handle->do_compress = false;
+}
+
+__hidden int out_uncompress_block(struct tracecmd_output *handle)
+{
+	int ret = 0;
+
+	if (!handle->compress)
+		return 0;
+
+	ret = tracecmd_uncompress_block(handle->compress);
+	if (!ret)
+		handle->do_compress = true;
+
+	return ret;
+}
+
+__hidden int out_compression_start(struct tracecmd_output *handle, bool compress)
+{
+	if (!compress || !handle->compress)
+		return 0;
+
+	tracecmd_compress_reset(handle->compress);
+	handle->do_compress = true;
+
+	return 0;
+}
+
+__hidden int out_compression_end(struct tracecmd_output *handle, bool compress)
+{
+	if (!compress || !handle->compress)
+		return 0;
+
+	handle->do_compress = false;
+	return tracecmd_compress_block(handle->compress);
+}
+
 static long add_string(struct tracecmd_output *handle, const char *string)
 {
 	int size = strlen(string) + 1;
@@ -1645,7 +1704,7 @@  static int append_options_v6(struct tracecmd_output *handle)
 	if (offset == (off_t)-1)
 		return -1;
 
-	r = pread(handle->fd, &option, 2, offset);
+	r = do_preed(handle, &option, 2, offset);
 	if (r != 2 || option != TRACECMD_OPTION_DONE)
 		return -1;