+/**
+ * collectd - src/utils_format_json.c
+ * Copyright (C) 2009 Florian octo Forster
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Authors:
+ * Florian octo Forster <octo at verplant.org>
+ **/
+
+#include "collectd.h"
+#include "plugin.h"
+#include "common.h"
+
+#include "utils_format_json.h"
+
+static int escape_string (char *buffer, size_t buffer_size, /* {{{ */
+ const char *string)
+{
+ size_t src_pos;
+ size_t dst_pos;
+
+ if ((buffer == NULL) || (string == NULL))
+ return (-EINVAL);
+
+ if (buffer_size < 3)
+ return (-ENOMEM);
+
+ dst_pos = 0;
+
+#define BUFFER_ADD(c) do { \
+ if (dst_pos >= (buffer_size - 1)) { \
+ buffer[buffer_size - 1] = 0; \
+ return (-ENOMEM); \
+ } \
+ buffer[dst_pos] = (c); \
+ dst_pos++; \
+} while (0)
+
+ /* Escape special characters */
+ BUFFER_ADD ('"');
+ for (src_pos = 0; string[src_pos] != 0; src_pos++)
+ {
+ if ((string[src_pos] == '"')
+ || (string[src_pos] == '\\'))
+ {
+ BUFFER_ADD ('\\');
+ BUFFER_ADD (string[src_pos]);
+ }
+ else if (string[src_pos] <= 0x001F)
+ BUFFER_ADD ('?');
+ else
+ BUFFER_ADD (string[src_pos]);
+ } /* for */
+ BUFFER_ADD ('"');
+ buffer[dst_pos] = 0;
+
+#undef BUFFER_ADD
+
+ return (0);
+} /* }}} int buffer_add_string */
+
+static int values_to_json (char *buffer, size_t buffer_size, /* {{{ */
+ const data_set_t *ds, const value_list_t *vl)
+{
+ size_t offset = 0;
+ int i;
+
+ memset (buffer, 0, buffer_size);
+
+#define BUFFER_ADD(...) do { \
+ int status; \
+ status = ssnprintf (buffer + offset, buffer_size - offset, \
+ __VA_ARGS__); \
+ if (status < 1) \
+ return (-1); \
+ else if (((size_t) status) >= (buffer_size - offset)) \
+ return (-ENOMEM); \
+ else \
+ offset += ((size_t) status); \
+} while (0)
+
+ BUFFER_ADD ("[");
+ for (i = 0; i < ds->ds_num; i++)
+ {
+ if (i > 0)
+ BUFFER_ADD (",");
+
+ if (ds->ds[i].type == DS_TYPE_GAUGE)
+ BUFFER_ADD ("%g", vl->values[i].gauge);
+ else if (ds->ds[i].type == DS_TYPE_COUNTER)
+ BUFFER_ADD ("%llu", vl->values[i].counter);
+ else if (ds->ds[i].type == DS_TYPE_DERIVE)
+ BUFFER_ADD ("%"PRIi64, vl->values[i].derive);
+ else if (ds->ds[i].type == DS_TYPE_ABSOLUTE)
+ BUFFER_ADD ("%"PRIu64, vl->values[i].absolute);
+ else
+ {
+ ERROR ("format_json: Unknown data source type: %i",
+ ds->ds[i].type);
+ return (-1);
+ }
+ } /* for ds->ds_num */
+ BUFFER_ADD ("]");
+
+#undef BUFFER_ADD
+
+ DEBUG ("format_json: values_to_json: buffer = %s;", buffer);
+
+ return (0);
+} /* }}} int values_to_json */
+
+static int value_list_to_json (char *buffer, size_t buffer_size, /* {{{ */
+ const data_set_t *ds, const value_list_t *vl)
+{
+ char temp[512];
+ size_t offset = 0;
+ int status;
+
+ memset (buffer, 0, buffer_size);
+
+#define BUFFER_ADD(...) do { \
+ status = ssnprintf (buffer + offset, buffer_size - offset, \
+ __VA_ARGS__); \
+ if (status < 1) \
+ return (-1); \
+ else if (((size_t) status) >= (buffer_size - offset)) \
+ return (-ENOMEM); \
+ else \
+ offset += ((size_t) status); \
+} while (0)
+
+ /* All value lists have a leading comma. The first one will be replaced with
+ * a square bracket in `format_json_finalize'. */
+ BUFFER_ADD (",{");
+
+ status = values_to_json (temp, sizeof (temp), ds, vl);
+ if (status != 0)
+ return (status);
+ BUFFER_ADD ("\"values\":%s", temp);
+
+ BUFFER_ADD (",\"time\":%lu", (unsigned long) vl->time);
+ BUFFER_ADD (",\"interval\":%i", vl->interval);
+
+#define BUFFER_ADD_KEYVAL(key, value) do { \
+ status = escape_string (temp, sizeof (temp), (value)); \
+ if (status != 0) \
+ return (status); \
+ BUFFER_ADD (",\"%s\":%s", (key), temp); \
+} while (0)
+
+ BUFFER_ADD_KEYVAL ("host", vl->host);
+ BUFFER_ADD_KEYVAL ("plugin", vl->plugin);
+ BUFFER_ADD_KEYVAL ("plugin_instance", vl->plugin_instance);
+ BUFFER_ADD_KEYVAL ("type", vl->type);
+ BUFFER_ADD_KEYVAL ("type_instance", vl->type_instance);
+
+ BUFFER_ADD ("}");
+
+#undef BUFFER_ADD_KEYVAL
+#undef BUFFER_ADD
+
+ DEBUG ("format_json: value_list_to_json: buffer = %s;", buffer);
+
+ return (0);
+} /* }}} int value_list_to_json */
+
+static int format_json_value_list_nocheck (char *buffer, /* {{{ */
+ size_t *ret_buffer_fill, size_t *ret_buffer_free,
+ const data_set_t *ds, const value_list_t *vl,
+ size_t temp_size)
+{
+ char temp[temp_size];
+ int status;
+
+ status = value_list_to_json (temp, sizeof (temp), ds, vl);
+ if (status != 0)
+ return (status);
+ temp_size = strlen (temp);
+
+ memcpy (buffer + (*ret_buffer_fill), temp, temp_size + 1);
+ (*ret_buffer_fill) += temp_size;
+ (*ret_buffer_free) -= temp_size;
+
+ return (0);
+} /* }}} int format_json_value_list_nocheck */
+
+int format_json_initialize (char *buffer, /* {{{ */
+ size_t *ret_buffer_fill, size_t *ret_buffer_free)
+{
+ size_t buffer_fill;
+ size_t buffer_free;
+
+ if ((buffer == NULL) || (ret_buffer_fill == NULL) || (ret_buffer_free == NULL))
+ return (-EINVAL);
+
+ buffer_fill = *ret_buffer_fill;
+ buffer_free = *ret_buffer_free;
+
+ buffer_free = buffer_fill + buffer_free;
+ buffer_fill = 0;
+
+ if (buffer_free < 3)
+ return (-ENOMEM);
+
+ memset (buffer, 0, buffer_free);
+ *ret_buffer_fill = buffer_fill;
+ *ret_buffer_free = buffer_free;
+
+ return (0);
+} /* }}} int format_json_initialize */
+
+int format_json_finalize (char *buffer, /* {{{ */
+ size_t *ret_buffer_fill, size_t *ret_buffer_free)
+{
+ size_t pos;
+
+ if ((buffer == NULL) || (ret_buffer_fill == NULL) || (ret_buffer_free == NULL))
+ return (-EINVAL);
+
+ if (*ret_buffer_free < 2)
+ return (-ENOMEM);
+
+ /* Replace the leading comma added in `value_list_to_json' with a square
+ * bracket. */
+ if (buffer[0] != ',')
+ return (-EINVAL);
+ buffer[0] = '[';
+
+ pos = *ret_buffer_fill;
+ buffer[pos] = ']';
+ buffer[pos+1] = 0;
+
+ (*ret_buffer_fill)++;
+ (*ret_buffer_free)--;
+
+ return (0);
+} /* }}} int format_json_finalize */
+
+int format_json_value_list (char *buffer, /* {{{ */
+ size_t *ret_buffer_fill, size_t *ret_buffer_free,
+ const data_set_t *ds, const value_list_t *vl)
+{
+ if ((buffer == NULL)
+ || (ret_buffer_fill == NULL) || (ret_buffer_free == NULL)
+ || (ds == NULL) || (vl == NULL))
+ return (-EINVAL);
+
+ if (*ret_buffer_free < 3)
+ return (-ENOMEM);
+
+ return (format_json_value_list_nocheck (buffer,
+ ret_buffer_fill, ret_buffer_free, ds, vl,
+ (*ret_buffer_free) - 2));
+} /* }}} int format_json_value_list */
+
+/* vim: set sw=2 sts=2 et fdm=marker : */