nghttp2_version: new function, returns info about this nghttp2

This returns run-time information about the lib

lib/Makefile.am

@@ -1,6 +1,6 @@
 # nghttp2 - HTTP/2.0 C Library
 
-# Copyright (c) 2012 Tatsuhiro Tsujikawa
+# Copyright (c) 2012, 2013 Tatsuhiro Tsujikawa
 
 # Permission is hereby granted, free of charge, to any person obtaining
 # a copy of this software and associated documentation files (the
@@ -37,7 +37,7 @@ OBJECTS = nghttp2_pq.c nghttp2_map.c nghttp2_queue.c \
 	nghttp2_session.c nghttp2_submit.c \
 	nghttp2_helper.c \
 	nghttp2_npn.c nghttp2_gzip.c \
-	nghttp2_hd.c
+	nghttp2_hd.c nghttp2_version.c
 
 HFILES = nghttp2_pq.h nghttp2_int.h nghttp2_map.h nghttp2_queue.h \
 	nghttp2_buffer.h nghttp2_frame.h \

lib/includes/nghttp2/nghttp2.h

@@ -58,6 +58,25 @@ struct nghttp2_session;
  */
 typedef struct nghttp2_session nghttp2_session;
 
+#define NGHTTP2_VERSION_AGE 1
+struct nghttp2_info {
+  int age; /* Age of this struct. This instance of nghttp2 sets it to
+              NGHTTP2_VERSION_AGE but a future version may bump it and add
+              more struct fields at the bottom */
+  int version_num;   /* the NGHTTP2_VERSION_NUM number */
+  const char *version_str; /* points to the NGHTTP2_VERSION string */
+  const char *proto_str;   /* points to the NGHTTP2_PROTO_VERSION_ID string
+                              this instance implements */
+  /* -------- the above fields all exist when age == 1 */
+};
+/**
+ * @struct
+ *
+ * This struct is what nghttp2_version() returns. It holds information about
+ * the particular nghttp2 version.
+ */
+typedef struct nghttp2_info nghttp2_info;
+
 /**
  * @macro
  *
@@ -1976,6 +1995,17 @@ int nghttp2_gzip_inflate(nghttp2_gzip *inflater,
                          uint8_t *out, size_t *outlen_ptr,
                          const uint8_t *in, size_t *inlen_ptr);
 
+/**
+ * @function
+ *
+ * Returns a pointer to a nghttp2_info struct with version information about
+ * the run-time library in use.  The |least_version| argument can be set to a
+ * 24 bit numerical value for the least accepted version number and if the
+ * condition is not met, this function will return a NULL. Pass in 0 to skip
+ * the version checking.
+ */
+nghttp2_info *nghttp2_version(int least_version);
+
 #ifdef __cplusplus
 }
 #endif

lib/nghttp2_version.c

@@ -0,0 +1,40 @@
+/*
+ * nghttp2 - HTTP/2.0 C Library
+ *
+ * Copyright (c) 2012, 2013 Tatsuhiro Tsujikawa
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <nghttp2/nghttp2.h>
+
+static nghttp2_info version = {
+  NGHTTP2_VERSION_AGE,
+  NGHTTP2_VERSION_NUM,
+  NGHTTP2_VERSION,
+  NGHTTP2_PROTO_VERSION_ID
+};
+
+nghttp2_info *nghttp2_version(int least_version)
+{
+  if(least_version > NGHTTP2_VERSION_NUM)
+    return NULL;
+  return &version;
+}