static ssize_t compress_iov_to_buffer(struct trace_record *target, const struct iovec *iov, int iovcnt)
{
if (NULL == iov) {
errno = EFAULT;
return -1;
}
if (iovcnt < 1) {
return 0;
}
char *src_buf = iov[0].iov_base;
size_t input_len = iov[0].iov_len;
size_t compressed_length = 0;
struct snappy_env env;
int rc = snappy_init_env(&env);
if (rc < 0) {
goto finish;
}
if (iovcnt > 1) {
/* TODO: Snappy should be able to accept an input IOV directly. Since this support is currently broken we use a workaround instead. */
input_len = total_iovec_len(iov, iovcnt);
src_buf = malloc(input_len);
if ((NULL == src_buf) || (copy_iov_to_buffer(src_buf, iov, iovcnt) != (ssize_t) input_len)) {
rc = -errno;
goto finish;
}
}
if (input_len > 0) {
/* Don't bother compressing trailing padding chars. Those will be re-inserted by the reader. */
input_len -= trace_r_count_chr_occurrences(src_buf + 1, input_len - 1, TRACE_UNUSED_SPACE_FILL_VALUE);
rc = snappy_compress(&env, src_buf, input_len, (char *)target, &compressed_length);
}
finish:
snappy_free_env(&env);
if (src_buf != iov[0].iov_base) {
free(src_buf);
}
if (0 != rc) {
errno = -rc;
ERR("Buffer compression failed with err", errno, strerror(errno));
return (ssize_t) -1;
}
TRACE_ASSERT(((ssize_t) compressed_length > 0) || (0 == input_len));
return (ssize_t) compressed_length;
}
ssize_t internal_buf_write_compressed(struct trace_internal_buf *buf, const struct iovec *iov, int iovcnt)
{
const size_t max_size = snappy_max_compressed_length(total_iovec_len(iov, iovcnt));
const size_t max_recs = internal_buf_bytes_to_recs(max_size);
const unsigned start_idx = internal_buf_alloc_space(buf, max_recs);
if (INTERNAL_BUF_INVALID_INDEX == start_idx) {
return -1;
}
const ssize_t compressed_len = compress_iov_to_buffer(buf->records + start_idx, iov, iovcnt);
if (compressed_len < 0) {
compactify_buffer(buf, start_idx, 0);
return -1;
}
compactify_buffer(buf, start_idx, internal_buf_bytes_to_recs(compressed_len));
fill_compression_remainder_with_pattern(buf, compressed_len);
return compressed_len;
}
static int trace_dumper_write(struct trace_dumper_configuration_s *conf, struct trace_record_file *record_file, const struct iovec *iov, int iovcnt)
{
int expected_bytes = total_iovec_len(iov, iovcnt);
int rc = 0;
if (conf->record_file.fd >= 0) {
rc = writev(record_file->fd, iov, iovcnt);
if (rc != expected_bytes) {
return -1;
}
record_file->records_written += expected_bytes / sizeof(struct trace_record);
}
if (conf->online) {
int parser_rc = dump_iovector_to_parser(conf, &conf->parser, iov, iovcnt);
if (parser_rc != 0) {
return -1;
}
}
return expected_bytes;
}
