lnstat: add json output format

diff --git a/misc/lnstat.c b/misc/lnstat.c
index 90198b734900e343699d629433e5eae5963a00f5..d6415efbb50cab3219cfe1f2a0438b60f79b24ce 100644 (file)
--- a/misc/lnstat.c
+++ b/misc/lnstat.c
@@ -41,7 +41,8 @@
 static struct option opts[] = {
        { "version", 0, NULL, 'V' },
        { "count", 1, NULL, 'c' },
-       { "dump", 1, NULL, 'd' },
+       { "dump", 0, NULL, 'd' },
+       { "json", 0, NULL, 'j' },
        { "file", 1, NULL, 'f' },
        { "help", 0, NULL, 'h' },
        { "interval", 1, NULL, 'i' },
@@ -63,6 +64,8 @@ static int usage(char *name, int exit_code)
                        "Print <count> number of intervals\n");
        fprintf(stderr, "\t-d --dump\t\t"
                        "Dump list of available files/keys\n");
+       fprintf(stderr, "\t-j --json\t\t"
+                       "Display in JSON format\n");
        fprintf(stderr, "\t-f --file <file>\tStatistics file to use\n");
        fprintf(stderr, "\t-h --help\t\tThis help message\n");
        fprintf(stderr, "\t-i --interval <intv>\t"
@@ -94,7 +97,7 @@ static void print_line(FILE *of, const struct lnstat_file *lnstat_files,
        int i;
 
        for (i = 0; i < fp->num; i++) {
-               struct lnstat_field *lf = fp->params[i].lf;
+               const struct lnstat_field *lf = fp->params[i].lf;
                char formatbuf[255];
 
                snprintf(formatbuf, sizeof(formatbuf)-1, "%%%ulu|",
@@ -104,6 +107,30 @@ static void print_line(FILE *of, const struct lnstat_file *lnstat_files,
        fputc('\n', of);
 }
 
+static void print_json(FILE *of, const struct lnstat_file *lnstat_files,
+                      const struct field_params *fp)
+{
+       int i;
+       const char *sep;
+       const char *base = NULL;
+
+       fputs("{\n", of);
+       for (i = 0; i < fp->num; i++) {
+               const struct lnstat_field *lf = fp->params[i].lf;
+               
+               if (!base || lf->file->basename != base) {
+                       if (base) fputs("},\n", of);
+                       base = lf->file->basename;
+                       sep = "\n\t";
+                       fprintf(of, "    \"%s\":{", base);
+               }
+               fprintf(of, "%s\"%s\":%lu", sep,
+                       lf->name, lf->result);
+               sep = ",\n\t";
+       }
+       fputs("}\n}\n", of);
+}
+
 /* find lnstat_field according to user specification */
 static int map_field_params(struct lnstat_file *lnstat_files,
                            struct field_params *fps, int interval)
@@ -218,15 +245,16 @@ int main(int argc, char **argv)
 {
        struct lnstat_file *lnstat_files;
        const char *basename;
-       int c;
+       int i, c;
        int interval = DEFAULT_INTERVAL;
        int hdr = 2;
        enum {
                MODE_DUMP,
+               MODE_JSON,
                MODE_NORMAL,
        } mode = MODE_NORMAL;
-
        unsigned long count = 1;
+       struct table_hdr *header;
        static struct field_params fp;
        int num_req_files = 0;
        char *req_files[LNSTAT_MAX_FILES];
@@ -248,70 +276,73 @@ int main(int argc, char **argv)
                num_req_files = 1;
        }
 
-       while ((c = getopt_long(argc, argv,"Vc:df:h?i:k:s:w:",
+       while ((c = getopt_long(argc, argv,"Vc:djf:h?i:k:s:w:",
                                opts, NULL)) != -1) {
-               int i, len = 0;
+               int len = 0;
                char *tmp, *tok;
 
                switch (c) {
-                       case 'c':
-                               count = strtoul(optarg, NULL, 0);
-                               break;
-                       case 'd':
-                               mode = MODE_DUMP;
-                               break;
-                       case 'f':
-                               req_files[num_req_files++] = strdup(optarg);
+               case 'c':
+                       count = strtoul(optarg, NULL, 0);
+                       break;
+               case 'd':
+                       mode = MODE_DUMP;
+                       break;
+               case 'j':
+                       mode = MODE_JSON;
+                       break;
+               case 'f':
+                       req_files[num_req_files++] = strdup(optarg);
+                       break;
+               case '?':
+               case 'h':
+                       usage(argv[0], 0);
+                       break;
+               case 'i':
+                       sscanf(optarg, "%u", &interval);
+                       break;
+               case 'k':
+                       tmp = strdup(optarg);
+                       if (!tmp)
                                break;
-                       case '?':
-                       case 'h':
-                               usage(argv[0], 0);
-                               break;
-                       case 'i':
-                               sscanf(optarg, "%u", &interval);
-                               break;
-                       case 'k':
-                               tmp = strdup(optarg);
-                               if (!tmp)
+                       for (tok = strtok(tmp, ",");
+                            tok;
+                            tok = strtok(NULL, ",")) {
+                               if (fp.num >= MAX_FIELDS) {
+                                       fprintf(stderr, 
+                                               "WARN: too many keys"
+                                               " requested: (%d max)\n",
+                                               MAX_FIELDS);
                                        break;
-                               for (tok = strtok(tmp, ",");
-                                    tok;
-                                    tok = strtok(NULL, ",")) {
-                                       if (fp.num >= MAX_FIELDS) {
-                                               fprintf(stderr, 
-                                                       "WARN: too many keys"
-                                                       " requested: (%d max)\n",
-                                                       MAX_FIELDS);
-                                               break;
-                                       }
-                                       fp.params[fp.num++].name = tok;
                                }
+                               fp.params[fp.num++].name = tok;
+                       }
+                       break;
+               case 's':
+                       sscanf(optarg, "%u", &hdr);
+                       break;
+               case 'w':
+                       tmp = strdup(optarg);
+                       if (!tmp)
                                break;
-                       case 's':
-                               sscanf(optarg, "%u", &hdr);
-                               break;
-                       case 'w':
-                               tmp = strdup(optarg);
-                               if (!tmp)
-                                       break;
-                               i = 0;
-                               for (tok = strtok(tmp, ",");
-                                    tok;
-                                    tok = strtok(NULL, ",")) {
-                                       len  = strtoul(tok, NULL, 0);
-                                       if (len > FIELD_WIDTH_MAX)
-                                               len = FIELD_WIDTH_MAX;
+                       i = 0;
+                       for (tok = strtok(tmp, ",");
+                            tok;
+                            tok = strtok(NULL, ",")) {
+                               len  = strtoul(tok, NULL, 0);
+                               if (len > FIELD_WIDTH_MAX)
+                                       len = FIELD_WIDTH_MAX;
+                               fp.params[i].print.width = len;
+                               i++;
+                       }
+                       if (i == 1) {
+                               for (i = 0; i < MAX_FIELDS; i++)
                                        fp.params[i].print.width = len;
-                                       i++;
-                               }
-                               if (i == 1) {
-                                       for (i = 0; i < MAX_FIELDS; i++)
-                                               fp.params[i].print.width = len;
-                               }
-                               break;
-                       default:
-                               usage(argv[0], 1);
-                               break;
+                       }
+                       break;
+               default:
+                       usage(argv[0], 1);
+                       break;
                }
        }
 
@@ -319,13 +350,12 @@ int main(int argc, char **argv)
                                       (const char **) req_files);
 
        switch (mode) {
-               int i;
-               struct table_hdr *header;
        case MODE_DUMP:
                lnstat_dump(stderr, lnstat_files);
                break;
-       case MODE_NORMAL:
 
+       case MODE_NORMAL:
+       case MODE_JSON:
                if (!map_field_params(lnstat_files, &fp, interval))
                        exit(1);
 
@@ -334,16 +364,23 @@ int main(int argc, char **argv)
                        exit(1);
 
                if (interval < 1 )
-                       interval=1;
+                       interval = 1;
 
                for (i = 0; i < count; i++) {
-                       if  ((hdr > 1 && (! (i % 20))) || (hdr == 1 && i == 0))
-                               print_hdr(stdout, header);
                        lnstat_update(lnstat_files);
-                       print_line(stdout, lnstat_files, &fp);
+                       if (mode == MODE_JSON)
+                               print_json(stdout, lnstat_files, &fp);
+                       else {
+                               if  ((hdr > 1 &&
+                                     (! (i % 20))) || (hdr == 1 && i == 0))
+                                       print_hdr(stdout, header);
+                               print_line(stdout, lnstat_files, &fp);
+                       }
                        fflush(stdout);
-                       sleep(interval);
+                       if (i < count - 1)
+                               sleep(interval);
                }
+               break;
        }
 
        return 1;