sys/log: Add option to limit number of printed logs

This adds -n option that can be used to specify number of
logs to print with log command.

Usage:
log -n <number>

i.e.:
log -n 10

will print at most 10 entries from each log

Signed-off-by: Jerzy Kasenberg <jerzy.kasenberg@codecoup.pl>

sys/log/full/src/log_shell.c

@@ -41,12 +41,25 @@
 
 static uint32_t shell_log_count;
 
+
+struct walk_arg {
+ uint32_t count_limit;
+ uint32_t count;
+};
+
 static int
 shell_log_count_entry(struct log *log, struct log_offset *log_offset,
  const struct log_entry_hdr *ueh, const void *dptr, uint16_t len)
 {
+ struct walk_arg *arg = (struct walk_arg *)log_offset->lo_arg;
+
  shell_log_count++;
- return 0;
+ if (arg) {
+ arg->count++;
+ if (arg->count >= arg->count_limit) {
+ return 1;
+ }
+ } return 0;
 }
 
 static int
@@ -59,6 +72,7 @@ shell_log_dump_entry(struct log *log, struct log_offset *log_offset,
  struct CborParser cbor_parser;
  struct CborValue cbor_value;
  struct log_cbor_reader cbor_reader;
+ struct walk_arg *arg = (struct walk_arg *)log_offset->lo_arg;
  char tmp[32 + 1];
  int off;
  int blksz;
@@ -108,6 +122,12 @@ shell_log_dump_entry(struct log *log, struct log_offset *log_offset,
  }
 
  console_write("\n", 1);
+ if (arg) {
+ arg->count++;
+ if (arg->count >= arg->count_limit) {
+ return 1;
+ }
+ }
  return 0;
 }
 
@@ -124,6 +144,7 @@ shell_log_dump_cmd(int argc, char **argv)
  bool partial_match = false;
  bool clear_log;
  bool dump_logs = true;
+ struct walk_arg arg = {};
  int i;
  int rc;
 
@@ -133,6 +154,17 @@ shell_log_dump_cmd(int argc, char **argv)
  list_only = true;
  break;
  }
+ if (0 == strcmp(argv[i], "-n")) {
+ if (i + 1 < argc) {
+ arg.count_limit = parse_ll_bounds(argv[i + 1], 1, 1000000, &rc);
+ if (rc) {
+ arg.count_limit = 1;
+ }
+ log_offset.lo_arg = &arg;
+ }
+ ++i;
+ continue;
+ }
  if (0 == strcmp(argv[i], "-t")) {
  dump_logs = false;
  continue;
@@ -187,8 +219,12 @@ shell_log_dump_cmd(int argc, char **argv)
  console_printf("Dumping log %s\n", log->l_name);
  }
 
- log_offset.lo_arg = NULL;
- log_offset.lo_ts = 0;
+ if (reverse) {
+ log_offset.lo_ts = -1;
+ log_offset.lo_walk_backward = true;
+ } else {
+ log_offset.lo_ts = 0;
+ }
  log_last_index = log_get_last_index(log);
  if (log_limit == 0 || log_last_index < log_limit) {
  log_offset.lo_index = 0;
@@ -241,8 +277,10 @@ shell_log_storage_cmd(int argc, char **argv)
  if (log_storage_info(log, &info)) {
  console_printf("Storage info not supported for %s\n", log->l_name);
  } else {
- console_printf("%s: %d of %d used\n", log->l_name,
- (unsigned)info.used, (unsigned)info.size);
+ uint32_t entry_count = 0;
+ log_get_entry_count(log, &entry_count);
+ console_printf("%s: %d of %d used; %d entries\n", log->l_name,
+ (unsigned)info.used, (unsigned)info.size, (int)entry_count);
 #if MYNEWT_VAL(LOG_STORAGE_WATERMARK)
  console_printf("%s: %d of %d used by unread entries\n", log->l_name,
  (unsigned)info.used_unread, (unsigned)info.size);