On Wed, 28 Jul 2021 16:31:34 +0300
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx> wrote:
> New library internal helper functions are introduced, to add compression
> functionality to the input trace handler.
>
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
> ---
> lib/trace-cmd/include/trace-cmd-local.h | 4 ++
> lib/trace-cmd/trace-input.c | 54 +++++++++++++++++++++----
> 2 files changed, 50 insertions(+), 8 deletions(-)
>
> diff --git a/lib/trace-cmd/include/trace-cmd-local.h b/lib/trace-cmd/include/trace-cmd-local.h
> index fa361766..670af8e4 100644
> --- a/lib/trace-cmd/include/trace-cmd-local.h
> +++ b/lib/trace-cmd/include/trace-cmd-local.h
> @@ -38,6 +38,10 @@ int out_uncompress_block(struct tracecmd_output *handle);
> int out_compression_start(struct tracecmd_output *handle);
> int out_compression_end(struct tracecmd_output *handle);
> void out_compression_reset(struct tracecmd_output *handle);
> +
> +void in_uncompress_reset(struct tracecmd_input *handle);
> +int in_uncompress_block(struct tracecmd_input *handle);
> +
> unsigned long long out_copy_fd_compress(struct tracecmd_output *handle,
> int fd, unsigned long long max,
> unsigned long long *write_size);
> diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
> index 38dd0deb..da6825b8 100644
> --- a/lib/trace-cmd/trace-input.c
> +++ b/lib/trace-cmd/trace-input.c
> @@ -136,6 +136,9 @@ struct tracecmd_input {
> long long ts_offset;
> struct tsc2nsec tsc_calc;
>
> + bool read_compress;
> + struct tracecmd_compression *compress;
> +
> struct host_trace_info host;
> double ts2secs;
> char * cpustats;
> @@ -238,13 +241,13 @@ static const char *show_records(struct page **pages, int nr_pages)
>
> static int init_cpu(struct tracecmd_input *handle, int cpu);
>
> -static ssize_t do_read(struct tracecmd_input *handle, void *data, size_t size)
> +static ssize_t do_read_fd(int fd, void *data, size_t size)
> {
> ssize_t tot = 0;
> ssize_t r;
>
> do {
> - r = read(handle->fd, data + tot, size - tot);
> + r = read(fd, data + tot, size - tot);
> tot += r;
>
> if (!r)
> @@ -256,12 +259,28 @@ static ssize_t do_read(struct tracecmd_input *handle, void *data, size_t size)
> return tot;
> }
>
> +static inline int do_lseek(struct tracecmd_input *handle, int offset, int whence)
> +{
> + if (handle->read_compress)
> + return tracecmd_compress_lseek(handle->compress, offset, whence);
> + else
> + return lseek(handle->fd, offset, whence);
> +}
> +
> +static inline ssize_t do_read_compressed(struct tracecmd_input *handle, void *data, size_t size)
This should be just called "do_read", as it handles both compressed and
normal reads. And the name suggests that it only does compressed reads.
> +{
> + if (handle->read_compress)
> + return tracecmd_compress_read(handle->compress, data, size);
> + else
> + return do_read_fd(handle->fd, data, size);
> +}
> +
> static ssize_t
> do_read_check(struct tracecmd_input *handle, void *data, size_t size)
> {
> ssize_t ret;
>
> - ret = do_read(handle, data, size);
> + ret = do_read_compressed(handle, data, size);
By keeping it do_read() you don't need all these other changes.
-- Steve
> if (ret < 0)
> return ret;
> if (ret != size)
> @@ -279,10 +298,8 @@ static char *read_string(struct tracecmd_input *handle)
> ssize_t r;
>
> for (;;) {
> - r = do_read(handle, buf, BUFSIZ);
> - if (r < 0)
> - goto fail;
> - if (!r)
> + r = do_read_compressed(handle, buf, BUFSIZ);
> + if (r <= 0)
> goto fail;
>
> for (i = 0; i < r; i++) {
> @@ -308,7 +325,7 @@ static char *read_string(struct tracecmd_input *handle)
> }
>
> /* move the file descriptor to the end of the string */
> - r = lseek(handle->fd, -(r - (i+1)), SEEK_CUR);
> + r = do_lseek(handle, -(r - (i+1)), SEEK_CUR);
> if (r < 0)
> goto fail;
>
> @@ -372,6 +389,26 @@ static int read8(struct tracecmd_input *handle, unsigned long long *size)
> return 0;
> }
>
> +__hidden void in_uncompress_reset(struct tracecmd_input *handle)
> +{
> + if (handle->compress) {
> + handle->read_compress = false;
> + tracecmd_compress_reset(handle->compress);
> + }
> +}
> +
> +__hidden int in_uncompress_block(struct tracecmd_input *handle)
> +{
> + int ret = 0;
> +
> + if (handle->compress) {
> + ret = tracecmd_uncompress_block(handle->compress);
> + if (!ret)
> + handle->read_compress = true;
> + }
> + return ret;
> +}
> +
> static int read_header_files(struct tracecmd_input *handle)
> {
> struct tep_handle *pevent = handle->pevent;
> @@ -479,6 +516,7 @@ static int read_ftrace_file(struct tracecmd_input *handle,
> buf = malloc(size);
> if (!buf)
> return -1;
> +
> if (do_read_check(handle, buf, size)) {
> free(buf);
> return -1;
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