also count number of downloads, not just the bytes

#ifdef INSTRUMENT_DOWNLOADS

/** Map used to keep track of how much data we've up/downloaded in what kind

 * of request.  Maps from request type to pointer to uint64_t. */

static strmap_t *request_bytes_map = NULL;

typedef struct request_t {

  uint64_t bytes;

  uint64_t count;

} request_t;

static strmap_t *request_map = NULL;

static void

note_client_request(int purpose, int compressed, size_t bytes)

  tor_free(key);

}

static void

ensure_request_map_initialized(void) {

  if (!request_map)

    request_map = strmap_new();

}

/** Called when we just transmitted or received <b>bytes</b> worth of data

 * because of a request of type <b>key</b> (an arbitrary identifier): adds

 * <b>bytes</b> to the total associated with key. */

void

note_request(const char *key, size_t bytes)

{

  uint64_t *n;

  if (!request_bytes_map)

    request_bytes_map = strmap_new();

  request_t *r;

  ensure_request_map_initialized();

  n = strmap_get(request_bytes_map, key);

  if (!n) {

    n = tor_malloc_zero(sizeof(uint64_t));

    strmap_set(request_bytes_map, key, n);

  r = strmap_get(request_map, key);

  if (!r) {

    r = tor_malloc_zero(sizeof(request_t));

    strmap_set(request_map, key, r);

  }

  *n += bytes;

  r->bytes += bytes;

  r->count++;

}

/** Return a newly allocated string holding a summary of bytes used per

  char *result;

  strmap_iter_t *iter;

  if (!request_bytes_map)

    request_bytes_map = strmap_new();

  ensure_request_map_initialized();

  lines = smartlist_create();

  for (iter = strmap_iter_init(request_bytes_map);

  for (iter = strmap_iter_init(request_map);

       !strmap_iter_done(iter);

       iter = strmap_iter_next(request_bytes_map, iter)) {

       iter = strmap_iter_next(request_map, iter)) {

    const char *key;

    void *val;

    uint64_t *n;

    request_t *r;

    strmap_iter_get(iter, &key, &val);

    n = val;

    tor_snprintf(tmp, sizeof(tmp), "%s  "U64_FORMAT"\n",

                 key, U64_PRINTF_ARG(*n));

    r = val;

    tor_snprintf(tmp, sizeof(tmp), "%s  "U64_FORMAT"  "U64_FORMAT"\n",

                 key, U64_PRINTF_ARG(r->bytes), U64_PRINTF_ARG(r->count));

    smartlist_add(lines, tor_strdup(tmp));

  }

  smartlist_sort_strings(lines);