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-rw-r--r--tools/perf/pmu-events/json.c162
1 files changed, 162 insertions, 0 deletions
diff --git a/tools/perf/pmu-events/json.c b/tools/perf/pmu-events/json.c
new file mode 100644
index 000000000..0544398d6
--- /dev/null
+++ b/tools/perf/pmu-events/json.c
@@ -0,0 +1,162 @@
+/* Parse JSON files using the JSMN parser. */
+
+/*
+ * Copyright (c) 2014, Intel Corporation
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include "jsmn.h"
+#include "json.h"
+#include <linux/kernel.h>
+
+
+static char *mapfile(const char *fn, size_t *size)
+{
+ unsigned ps = sysconf(_SC_PAGESIZE);
+ struct stat st;
+ char *map = NULL;
+ int err;
+ int fd = open(fn, O_RDONLY);
+
+ if (fd < 0 && verbose > 0 && fn) {
+ pr_err("Error opening events file '%s': %s\n", fn,
+ strerror(errno));
+ }
+
+ if (fd < 0)
+ return NULL;
+ err = fstat(fd, &st);
+ if (err < 0)
+ goto out;
+ *size = st.st_size;
+ map = mmap(NULL,
+ (st.st_size + ps - 1) & ~(ps - 1),
+ PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
+ if (map == MAP_FAILED)
+ map = NULL;
+out:
+ close(fd);
+ return map;
+}
+
+static void unmapfile(char *map, size_t size)
+{
+ unsigned ps = sysconf(_SC_PAGESIZE);
+ munmap(map, roundup(size, ps));
+}
+
+/*
+ * Parse json file using jsmn. Return array of tokens,
+ * and mapped file. Caller needs to free array.
+ */
+jsmntok_t *parse_json(const char *fn, char **map, size_t *size, int *len)
+{
+ jsmn_parser parser;
+ jsmntok_t *tokens;
+ jsmnerr_t res;
+ unsigned sz;
+
+ *map = mapfile(fn, size);
+ if (!*map)
+ return NULL;
+ /* Heuristic */
+ sz = *size * 16;
+ tokens = malloc(sz);
+ if (!tokens)
+ goto error;
+ jsmn_init(&parser);
+ res = jsmn_parse(&parser, *map, *size, tokens,
+ sz / sizeof(jsmntok_t));
+ if (res != JSMN_SUCCESS) {
+ pr_err("%s: json error %s\n", fn, jsmn_strerror(res));
+ goto error_free;
+ }
+ if (len)
+ *len = parser.toknext;
+ return tokens;
+error_free:
+ free(tokens);
+error:
+ unmapfile(*map, *size);
+ return NULL;
+}
+
+void free_json(char *map, size_t size, jsmntok_t *tokens)
+{
+ free(tokens);
+ unmapfile(map, size);
+}
+
+static int countchar(char *map, char c, int end)
+{
+ int i;
+ int count = 0;
+ for (i = 0; i < end; i++)
+ if (map[i] == c)
+ count++;
+ return count;
+}
+
+/* Return line number of a jsmn token */
+int json_line(char *map, jsmntok_t *t)
+{
+ return countchar(map, '\n', t->start) + 1;
+}
+
+static const char * const jsmn_types[] = {
+ [JSMN_PRIMITIVE] = "primitive",
+ [JSMN_ARRAY] = "array",
+ [JSMN_OBJECT] = "object",
+ [JSMN_STRING] = "string"
+};
+
+#define LOOKUP(a, i) ((i) < (sizeof(a)/sizeof(*(a))) ? ((a)[i]) : "?")
+
+/* Return type name of a jsmn token */
+const char *json_name(jsmntok_t *t)
+{
+ return LOOKUP(jsmn_types, t->type);
+}
+
+int json_len(jsmntok_t *t)
+{
+ return t->end - t->start;
+}
+
+/* Is string t equal to s? */
+int json_streq(char *map, jsmntok_t *t, const char *s)
+{
+ unsigned len = json_len(t);
+ return len == strlen(s) && !strncasecmp(map + t->start, s, len);
+}