lib/trace_parser: map/unmap the trace file

Copied code responsible for mapping/unmapping the trace file.  The
only modifications were related with tying it to the spdk_trace_parser
object.

Signed-off-by: Konrad Sztyber <konrad.sztyber@intel.com>
Change-Id: Ia575101532c612b185bd971c69157623b52b9e81
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/9429
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Community-CI: Mellanox Build Bot
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>

lib/trace_parser/trace.cpp

@@ -32,14 +32,129 @@
  */
 
 #include "spdk/stdinc.h"
+#include "spdk/log.h"
 #include "spdk/trace_parser.h"
 
+#include <exception>
+#include <new>
+
+struct spdk_trace_parser {
+	spdk_trace_parser(const spdk_trace_parser_opts *opts);
+	~spdk_trace_parser();
+	spdk_trace_parser(const spdk_trace_parser &) = delete;
+	spdk_trace_parser &operator=(const spdk_trace_parser &) = delete;
+private:
+	bool init(const spdk_trace_parser_opts *opts);
+	void cleanup();
+
+	spdk_trace_histories	*_histories;
+	size_t			_map_size;
+	int			_fd;
+};
+
+bool
+spdk_trace_parser::init(const spdk_trace_parser_opts *opts)
+{
+	struct stat st;
+	int rc;
+
+	switch (opts->mode) {
+	case SPDK_TRACE_PARSER_MODE_FILE:
+		_fd = open(opts->filename, O_RDONLY);
+		break;
+	case SPDK_TRACE_PARSER_MODE_SHM:
+		_fd = shm_open(opts->filename, O_RDONLY, 0600);
+		break;
+	default:
+		SPDK_ERRLOG("Invalid mode: %d\n", opts->mode);
+		return false;
+	}
+
+	if (_fd < 0) {
+		SPDK_ERRLOG("Could not open trace file: %s (%d)\n", opts->filename, errno);
+		return false;
+	}
+
+	rc = fstat(_fd, &st);
+	if (rc < 0) {
+		SPDK_ERRLOG("Could not get size of trace file: %s\n", opts->filename);
+		return false;
+	}
+
+	if ((size_t)st.st_size < sizeof(*_histories)) {
+		SPDK_ERRLOG("Invalid trace file: %s\n", opts->filename);
+		return false;
+	}
+
+	/* Map the header of trace file */
+	_map_size = sizeof(*_histories);
+	_histories = static_cast<spdk_trace_histories *>(mmap(NULL, _map_size, PROT_READ,
+			MAP_SHARED, _fd, 0));
+	if (_histories == MAP_FAILED) {
+		SPDK_ERRLOG("Could not mmap trace file: %s\n", opts->filename);
+		_histories = NULL;
+		return false;
+	}
+
+	/* Remap the entire trace file */
+	_map_size = spdk_get_trace_histories_size(_histories);
+	munmap(_histories, sizeof(*_histories));
+	if ((size_t)st.st_size < _map_size) {
+		SPDK_ERRLOG("Trace file %s is not valid\n", opts->filename);
+		_histories = NULL;
+		return false;
+	}
+	_histories = static_cast<spdk_trace_histories *>(mmap(NULL, _map_size, PROT_READ,
+			MAP_SHARED, _fd, 0));
+	if (_histories == MAP_FAILED) {
+		SPDK_ERRLOG("Could not mmap trace file: %s\n", opts->filename);
+		_histories = NULL;
+		return false;
+	}
+
+	return true;
+}
+
+void
+spdk_trace_parser::cleanup()
+{
+	if (_histories != NULL) {
+		munmap(_histories, _map_size);
+	}
+
+	if (_fd > 0) {
+		close(_fd);
+	}
+}
+
+spdk_trace_parser::spdk_trace_parser(const spdk_trace_parser_opts *opts) :
+	_histories(NULL),
+	_map_size(0),
+	_fd(-1)
+{
+	if (!init(opts)) {
+		cleanup();
+		throw std::exception();
+	}
+}
+
+spdk_trace_parser::~spdk_trace_parser()
+{
+	cleanup();
+}
+
 struct spdk_trace_parser *
 spdk_trace_parser_init(const struct spdk_trace_parser_opts *opts)
 {
-	return NULL;
+	try {
+		return new spdk_trace_parser(opts);
+	} catch (...) {
+		return NULL;
+	}
 }
 
 void
 spdk_trace_parser_cleanup(struct spdk_trace_parser *parser)
-{}
+{
+	delete parser;
+}

mk/spdk.lib_deps.mk

@@ -52,6 +52,7 @@ DEPDIRS-sock := log $(JSON_LIBS)
 DEPDIRS-util := log
 DEPDIRS-vmd := log
 DEPDIRS-dma := log
+DEPDIRS-trace_parser := log
 ifeq ($(CONFIG_VFIO_USER),y)
 DEPDIRS-vfio_user := log
 endif