X-Git-Url: https://git.tokkee.org/?p=sysdb.git;a=blobdiff_plain;f=src%2Fcore%2Fstore_json.c;h=a069d8543872ea79e20edd8f31c0355f372488dd;hp=493ac9f377c9072d54fdf76488ab242e76cc6ec6;hb=ed2c9fc3e4ca6840a5a31c735f0cfc02fd21d4fc;hpb=914549be3bfffdd3ad4b2599ed1e771d857512da

diff --git a/src/core/store_json.c b/src/core/store_json.c
index 493ac9f..a069d85 100644
--- a/src/core/store_json.c
+++ b/src/core/store_json.c
@@ -1,6 +1,6 @@
 /*
  * SysDB - src/core/store_json.c
- * Copyright (C) 2013-2014 Sebastian 'tokkee' Harl <sh@tokkee.org>
+ * Copyright (C) 2013-2015 Sebastian 'tokkee' Harl <sh@tokkee.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -39,13 +39,18 @@
 
 #include <assert.h>
 
+#include <ctype.h>
 #include <stdlib.h>
+#include <string.h>
 
 /*
  * private data types
  */
 
 struct sdb_store_json_formatter {
+	sdb_object_t super;
+
+	/* The string buffer to write to */
 	sdb_strbuf_t *buf;
 
 	/* The context describes the state of the formatter through
@@ -53,49 +58,187 @@ struct sdb_store_json_formatter {
 	int context[8];
 	size_t current;
 
-	/* The current host context when processing non-host objects */
-	sdb_store_obj_t *current_host;
-
 	int type;
 	int flags;
 };
+#define F(obj) ((sdb_store_json_formatter_t *)(obj))
+
+static int
+formatter_init(sdb_object_t *obj, va_list ap)
+{
+	sdb_store_json_formatter_t *f = F(obj);
+
+	f->buf = va_arg(ap, sdb_strbuf_t *);
+	if (! f->buf)
+		return -1;
+
+	f->type = va_arg(ap, int);
+	if ((f->type != SDB_HOST) && (f->type != SDB_SERVICE) && (f->type != SDB_METRIC))
+		return -1;
+
+	f->flags = va_arg(ap, int);
+
+	f->context[0] = 0;
+	f->current = 0;
+	return 0;
+} /* formatter_init */
+
+static sdb_type_t formatter_type = {
+	/* size = */ sizeof(sdb_store_json_formatter_t),
+	/* init = */ formatter_init,
+	/* destroy = */ NULL,
+};
+
+/* A generic representation of a stored object. */
+typedef struct {
+	/* identifier */
+	int type;
+	const char *name;
+
+	/* attribute value (optional) */
+	sdb_data_t *value;
+
+	/* metric's timeseries (optional)
+	 * -1: unset
+	 *  0: false
+	 *  1: true */
+	int timeseries;
+
+	/* generic meta-data */
+	sdb_time_t last_update;
+	sdb_time_t interval;
+	size_t backends_num;
+	const char * const *backends;
+} obj_t;
 
 /*
  * private helper functions
  */
 
+static void
+escape_string(const char *src, char *dest)
+{
+	size_t i = 1;
+	dest[0] = '"';
+	for ( ; *src; ++src) {
+		char c = *src;
+		if ((c == '"') || (c == '\\') || iscntrl((int)c)) {
+			dest[i] = '\\';
+			++i;
+		}
+		switch (c) {
+			case '\a': dest[i] = 'a'; break;
+			case '\b': dest[i] = 'b'; break;
+			case '\t': dest[i] = 't'; break;
+			case '\n': dest[i] = 'n'; break;
+			case '\v': dest[i] = 'v'; break;
+			case '\f': dest[i] = 'f'; break;
+			case '\r': dest[i] = 'r'; break;
+			default: dest[i] = c; break;
+		}
+		++i;
+	}
+	dest[i] = '"';
+	dest[i + 1] = '\0';
+} /* escape_string */
+
+/* handle_new_object takes care of all maintenance logic related to adding a
+ * new object. That is, it manages context information and emit the prefix and
+ * suffix of an object. */
 static int
-json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj)
+handle_new_object(sdb_store_json_formatter_t *f, int type)
+{
+	/* first top-level object */
+	if (! f->context[0]) {
+		if ((type != f->type) && (type != SDB_HOST)) {
+			sdb_log(SDB_LOG_ERR, "store: Unexpected object of type %s "
+					"as the first element during %s JSON serialization",
+					SDB_STORE_TYPE_TO_NAME(type),
+					SDB_STORE_TYPE_TO_NAME(f->type));
+			return -1;
+		}
+		if (f->flags & SDB_WANT_ARRAY)
+			sdb_strbuf_append(f->buf, "[");
+		assert(f->current == 0);
+		f->context[f->current] = type;
+		return 0;
+	}
+
+	if ((f->context[f->current] != SDB_HOST)
+			&& (type != SDB_ATTRIBUTE)) {
+		/* new entry of the same type or a parent object;
+		 * rewind to the right state */
+		while ((f->current > 0)
+				&& (f->context[f->current] != type)) {
+			sdb_strbuf_append(f->buf, "}]");
+			--f->current;
+		}
+	}
+
+	if (type == f->context[f->current]) {
+		/* new entry of the same type */
+		sdb_strbuf_append(f->buf, "},");
+	}
+	else if ((f->context[f->current] == SDB_HOST)
+			|| (type == SDB_ATTRIBUTE)) {
+		assert(type != SDB_HOST);
+		/* all object types may be children of a host;
+		 * attributes may be children of any type */
+		sdb_strbuf_append(f->buf, ", \"%ss\": [",
+				SDB_STORE_TYPE_TO_NAME(type));
+		++f->current;
+	}
+	else {
+		sdb_log(SDB_LOG_ERR, "store: Unexpected object of type %s "
+				"on level %zu during JSON serialization",
+				SDB_STORE_TYPE_TO_NAME(type), f->current);
+		return -1;
+	}
+
+	assert(f->current < SDB_STATIC_ARRAY_LEN(f->context));
+	f->context[f->current] = type;
+	return 0;
+} /* handle_new_object */
+
+static int
+json_emit(sdb_store_json_formatter_t *f, obj_t *obj)
 {
 	char time_str[64];
 	char interval_str[64];
+	char name[2 * strlen(obj->name) + 3];
 	size_t i;
 
 	assert(f && obj);
 
-	if ((f->type != SDB_HOST) && (f->type == obj->type)) {
-		/* create the host for the current entry first */
-		assert(obj->parent && (obj->parent->type == SDB_HOST));
-		if (f->current_host != obj->parent) {
-			json_emit(f, obj->parent);
-			sdb_strbuf_append(f->buf, ", \"%ss\": [",
-					SDB_STORE_TYPE_TO_NAME(obj->type));
-			f->current_host = obj->parent;
-		}
-	}
+	handle_new_object(f, obj->type);
 
-	sdb_strbuf_append(f->buf, "{\"name\": \"%s\", ", SDB_OBJ(obj)->name);
-	if (obj->type == SDB_ATTRIBUTE) {
-		char tmp[sdb_data_strlen(&ATTR(obj)->value) + 1];
-		if (sdb_data_format(&ATTR(obj)->value, tmp, sizeof(tmp),
-					SDB_DOUBLE_QUOTED) < 0)
+	escape_string(obj->name, name);
+	sdb_strbuf_append(f->buf, "{\"name\": %s, ", name);
+	if ((obj->type == SDB_ATTRIBUTE) && (obj->value)) {
+		char tmp[sdb_data_strlen(obj->value) + 1];
+		char val[2 * sizeof(tmp) + 3];
+		if (! sdb_data_format(obj->value, tmp, sizeof(tmp),
+					SDB_DOUBLE_QUOTED))
 			snprintf(tmp, sizeof(tmp), "<error>");
-		sdb_strbuf_append(f->buf, "\"value\": %s, ", tmp);
+
+		if (tmp[0] == '"') {
+			/* a string; escape_string handles quoting */
+			tmp[strlen(tmp) - 1] = '\0';
+			escape_string(tmp + 1, val);
+			sdb_strbuf_append(f->buf, "\"value\": %s, ", val);
+		}
+		else
+			sdb_strbuf_append(f->buf, "\"value\": %s, ", tmp);
+	}
+	else if ((obj->type == SDB_METRIC) && (obj->timeseries >= 0)) {
+		if (obj->timeseries)
+			sdb_strbuf_append(f->buf, "\"timeseries\": true, ");
+		else
+			sdb_strbuf_append(f->buf, "\"timeseries\": false, ");
 	}
 
 	/* TODO: make time and interval formats configurable */
-	if (! sdb_strftime(time_str, sizeof(time_str),
-				"%F %T %z", obj->last_update))
+	if (! sdb_strftime(time_str, sizeof(time_str), obj->last_update))
 		snprintf(time_str, sizeof(time_str), "<error>");
 	time_str[sizeof(time_str) - 1] = '\0';
 
@@ -117,34 +260,123 @@ json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj)
 	return 0;
 } /* json_emit */
 
-/*
- * public API
- */
+static int
+emit_host(sdb_store_host_t *host, sdb_object_t *user_data)
+{
+	sdb_store_json_formatter_t *f = F(user_data);
 
-sdb_store_json_formatter_t *
-sdb_store_json_formatter(sdb_strbuf_t *buf, int type, int flags)
+	if ((! host) || (! user_data))
+		return -1;
+
+	{
+		obj_t o = {
+			SDB_HOST,
+			host->name,
+
+			/* value */ NULL,
+			/* timeseries */ -1,
+
+			host->last_update,
+			host->interval,
+			host->backends_num,
+			(const char * const *)host->backends,
+		};
+
+		return json_emit(f, &o);
+	}
+} /* emit_host */
+
+static int
+emit_service(sdb_store_service_t *service, sdb_object_t *user_data)
 {
-	sdb_store_json_formatter_t *f;
+	sdb_store_json_formatter_t *f = F(user_data);
 
-	if (! buf)
-		return NULL;
+	if ((! service) || (! user_data))
+		return -1;
 
-	if ((type != SDB_HOST) && (type != SDB_SERVICE) && (type != SDB_METRIC))
-		return NULL;
+	{
+		obj_t o = {
+			SDB_SERVICE,
+			service->name,
 
-	f = calloc(1, sizeof(*f));
-	if (! f)
-		return NULL;
+			/* value */ NULL,
+			/* timeseries */ -1,
 
-	f->buf = buf;
-	f->context[0] = 0;
-	f->current = 0;
+			service->last_update,
+			service->interval,
+			service->backends_num,
+			(const char * const *)service->backends,
+		};
+
+		return json_emit(f, &o);
+	}
+} /* emit_service */
+
+static int
+emit_metric(sdb_store_metric_t *metric, sdb_object_t *user_data)
+{
+	sdb_store_json_formatter_t *f = F(user_data);
+
+	if ((! metric) || (! user_data))
+		return -1;
+
+	{
+		obj_t o = {
+			SDB_METRIC,
+			metric->name,
+
+			/* value */ NULL,
+			/* timeseries */ metric->store.type != NULL,
+
+			metric->last_update,
+			metric->interval,
+			metric->backends_num,
+			(const char * const *)metric->backends,
+		};
 
-	f->current_host = NULL;
+		return json_emit(f, &o);
+	}
+} /* emit_metric */
+
+static int
+emit_attribute(sdb_store_attribute_t *attr, sdb_object_t *user_data)
+{
+	sdb_store_json_formatter_t *f = F(user_data);
+
+	if ((! attr) || (! user_data))
+		return -1;
+
+	{
+		obj_t o = {
+			SDB_ATTRIBUTE,
+			attr->key,
+
+			/* value */ &attr->value,
+			/* timeseries */ -1,
+
+			attr->last_update,
+			attr->interval,
+			attr->backends_num,
+			(const char * const *)attr->backends,
+		};
+
+		return json_emit(f, &o);
+	}
+} /* emit_attribute */
+
+/*
+ * public API
+ */
 
-	f->type = type;
-	f->flags = flags;
-	return f;
+sdb_store_writer_t sdb_store_json_writer = {
+	emit_host, emit_service, emit_metric, emit_attribute,
+};
+
+sdb_store_json_formatter_t *
+sdb_store_json_formatter(sdb_strbuf_t *buf, int type, int flags)
+{
+	return F(sdb_object_create("json-formatter", formatter_type,
+				buf, type, flags));
 } /* sdb_store_json_formatter */
 
 int
@@ -153,67 +385,67 @@ sdb_store_json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj)
 	if ((! f) || (! obj))
 		return -1;
 
-	if ((f->type != SDB_HOST) && (obj->type == SDB_HOST)) {
-		sdb_log(SDB_LOG_ERR, "store: Unexpected object of type host "
-				"during %s JSON serialization",
-				SDB_STORE_TYPE_TO_NAME(f->type));
-		return -1;
-	}
-
-	/* first top-level object */
-	if (! f->context[0]) {
-		if (obj->type != f->type) {
-			sdb_log(SDB_LOG_ERR, "store: Unexpected object of type %s "
-					"as the first element during %s JSON serialization",
-					SDB_STORE_TYPE_TO_NAME(obj->type),
-					SDB_STORE_TYPE_TO_NAME(f->type));
-			return -1;
+	switch (obj->type) {
+	case SDB_HOST:
+		{
+			sdb_store_host_t host = {
+				obj->_name,
+				obj->last_update,
+				obj->interval,
+				(const char * const *)obj->backends,
+				obj->backends_num,
+			};
+			return sdb_store_json_writer.store_host(&host, SDB_OBJ(f));
 		}
-		if (f->flags & SDB_WANT_ARRAY)
-			sdb_strbuf_append(f->buf, "[");
-		assert(f->current == 0);
-		f->context[0] = obj->type;
-		return json_emit(f, obj);
-	}
-
-	if ((f->current >= 1) && (obj->type != SDB_ATTRIBUTE)) {
-		/* new entry of a previous type or a new type on the same level;
-		 * rewind to the right state */
-		while (f->current > 0) {
-			if (f->context[f->current] == obj->type)
-				break;
-			sdb_strbuf_append(f->buf, "}]");
-			--f->current;
+	case SDB_SERVICE:
+		{
+			sdb_store_service_t service = {
+				obj->parent ? obj->parent->_name : NULL,
+				obj->_name,
+				obj->last_update,
+				obj->interval,
+				(const char * const *)obj->backends,
+				obj->backends_num,
+			};
+			return sdb_store_json_writer.store_service(&service, SDB_OBJ(f));
+		}
+	case SDB_METRIC:
+		{
+			sdb_store_metric_t metric = {
+				obj->parent ? obj->parent->_name : NULL,
+				obj->_name,
+				{
+					METRIC(obj)->store.type,
+					METRIC(obj)->store.id,
+				},
+				obj->last_update,
+				obj->interval,
+				(const char * const *)obj->backends,
+				obj->backends_num,
+			};
+			return sdb_store_json_writer.store_metric(&metric, SDB_OBJ(f));
+		}
+	case SDB_ATTRIBUTE:
+		{
+			sdb_store_attribute_t attr = {
+				NULL,
+				obj->parent ? obj->parent->type : 0,
+				obj->parent ? obj->parent->_name : NULL,
+				obj->_name,
+				ATTR(obj)->value,
+				obj->last_update,
+				obj->interval,
+				(const char * const *)obj->backends,
+				obj->backends_num,
+			};
+			if (obj->parent && (obj->parent->type != SDB_HOST)
+					&& obj->parent->parent)
+				attr.hostname = obj->parent->parent->_name;
+			return sdb_store_json_writer.store_attribute(&attr, SDB_OBJ(f));
 		}
-	}
-	if ((obj->type == f->type) && (f->type != SDB_HOST))
-		if (obj->parent != f->current_host)
-			sdb_strbuf_append(f->buf, "}]");
-
-	if (obj->type == f->context[f->current]) {
-		/* new entry of the same type */
-		sdb_strbuf_append(f->buf, "},");
-	}
-	else if ((f->context[f->current] == SDB_HOST)
-			|| (obj->type == SDB_ATTRIBUTE)) {
-		assert(obj->type != SDB_HOST);
-		/* all object types may be children of a host;
-		 * attributes may be children of any type */
-		sdb_strbuf_append(f->buf, ", \"%ss\": [",
-				SDB_STORE_TYPE_TO_NAME(obj->type));
-		++f->current;
-	}
-	else {
-		sdb_log(SDB_LOG_ERR, "store: Unexpected object of type %s "
-				"on level %zu during JSON serialization",
-				SDB_STORE_TYPE_TO_NAME(obj->type), f->current);
-		return -1;
 	}
 
-	json_emit(f, obj);
-	assert(f->current < SDB_STATIC_ARRAY_LEN(f->context));
-	f->context[f->current] = obj->type;
-	return 0;
+	return -1;
 } /* sdb_store_json_emit */
 
 int
@@ -281,12 +513,7 @@ sdb_store_json_finish(sdb_store_json_formatter_t *f)
 		sdb_strbuf_append(f->buf, "}]");
 		--f->current;
 	}
-	if (f->context[0] != SDB_HOST) {
-		assert(f->type != SDB_HOST);
-		sdb_strbuf_append(f->buf, "}]}");
-	}
-	else
-		sdb_strbuf_append(f->buf, "}");
+	sdb_strbuf_append(f->buf, "}");
 
 	if (f->flags & SDB_WANT_ARRAY)
 		sdb_strbuf_append(f->buf, "]");