Merge pull request pramsey#35 from tbussmann/master

Add HEAD method

META.json

@@ -2,7 +2,7 @@
    "name": "http",
    "abstract": "HTTP client for PostgreSQL",
    "description": "HTTP allows you to get the content of a web page in a SQL function call.",
-   "version": "1.1",
+   "version": "1.2",
    "maintainer": [
       "Paul Ramsey <[email protected]>"
    ],
@@ -21,9 +21,9 @@
    },
    "provides": {
      "http": {
-       "file": "http--1.1.sql",
+       "file": "http--1.2.sql",
        "docfile": "README.md",
-       "version": "1.1",
+       "version": "1.2",
        "abstract": "HTTP client for PostgreSQL"
      },
    },

Makefile

@@ -2,7 +2,7 @@
 MODULE_big = http
 OBJS = http.o
 EXTENSION = http
-DATA = http--1.1.sql http--1.0--1.1.sql
+DATA = http--1.2.sql http--1.1--1.2.sql http--1.0--1.1.sql
 REGRESS = http
 EXTRA_CLEAN =
 

README.md

@@ -123,6 +123,22 @@ To access binary content, you must coerce the content from the default `varchar`
     --------------+---------------+----------------
      image/gif    |         31958 | 31958
 
+To access only the headers you can do a HEAD-Request. This will not follow redirections.
+
+    SELECT 
+        http.status, 
+        headers.value AS location
+    FROM 
+        http_head('http://google.com') AS http
+        LEFT OUTER JOIN LATERAL (SELECT value  
+            FROM unnest(http.headers) 
+            WHERE field = 'Location') AS headers
+            ON true;
+
+     status |                         location                          
+    --------+-----------------------------------------------------------
+        302 | http://www.google.ch/?gfe_rd=cr&ei=ACESWLy_KuvI8zeghL64Ag
+
 ## Concepts
 
 Every HTTP call is a made up of an `http_request` and an `http_response`.
@@ -144,7 +160,7 @@ Every HTTP call is a made up of an `http_request` and an `http_response`.
      headers      | http_header[]     | 
      content      | character varying | 
 
-The utility functions, `http_get()`, `http_post()`, `http_put()`, and `http_delete()` are just wrappers around a master function, `http(http_request)` that returns `http_response`.
+The utility functions, `http_get()`, `http_post()`, `http_put()`, `http_delete()` and `http_head()` are just wrappers around a master function, `http(http_request)` that returns `http_response`.
 
 The `headers` field for requests and response is a PostgreSQL array of type `http_header` which is just a simple tuple.
 
@@ -178,6 +194,7 @@ By default a 5 second timeout is set for the completion of a request.  If a diff
 * `http_post(uri VARCHAR, content VARCHAR, content_type VARCHAR)` returns `http_response`
 * `http_put(uri VARCHAR, content VARCHAR, content_type VARCHAR)` returns `http_response`
 * `http_delete(uri VARCHAR)` returns `http_resonse`
+* `http_head(uri VARCHAR)` returns `http_resonse`
 * `urlencode(string VARCHAR)` returns `text`
 
 ## Installation

http--1.1--1.2.sql

@@ -0,0 +1,14 @@
+
+ALTER DOMAIN http_method DROP CONSTRAINT http_method_check;
+ALTER DOMAIN http_method ADD CHECK (
+    VALUE ILIKE 'get' OR
+    VALUE ILIKE 'post' OR
+    VALUE ILIKE 'put' OR
+    VALUE ILIKE 'delete' OR
+    VALUE ILIKE 'head'
+);
+
+CREATE OR REPLACE FUNCTION http_head(uri VARCHAR)
+    RETURNS http_response
+    AS $$ SELECT http(('HEAD', $1, NULL, NULL, NULL)::http_request) $$
+    LANGUAGE 'sql';

http--1.1.sql → http--1.2.sql

@@ -6,7 +6,8 @@ CHECK (
     VALUE ILIKE 'get' OR
     VALUE ILIKE 'post' OR
     VALUE ILIKE 'put' OR
-    VALUE ILIKE 'delete'
+    VALUE ILIKE 'delete' OR
+    VALUE ILIKE 'head'
 );
 
 CREATE DOMAIN content_type AS text
@@ -63,6 +64,11 @@ CREATE OR REPLACE FUNCTION http_delete(uri VARCHAR)
     RETURNS http_response
     AS $$ SELECT http(('DELETE', $1, NULL, NULL, NULL)::http_request) $$
     LANGUAGE 'sql';
+
+CREATE OR REPLACE FUNCTION http_head(uri VARCHAR)
+    RETURNS http_response
+    AS $$ SELECT http(('HEAD', $1, NULL, NULL, NULL)::http_request) $$
+    LANGUAGE 'sql';
 
 CREATE OR REPLACE FUNCTION urlencode(string VARCHAR)
     RETURNS TEXT

http.c

@@ -70,7 +70,8 @@ typedef enum {
 	HTTP_GET,
 	HTTP_POST,
 	HTTP_DELETE,
-	HTTP_PUT
+	HTTP_PUT,
+	HTTP_HEAD
 } http_method;
 
 /* Components (and postitions) of the http_request tuple type */
@@ -213,6 +214,8 @@ request_type(const char *method)
 		return HTTP_PUT;
 	else if ( strcasecmp(method, "DELETE") == 0 )
 		return HTTP_DELETE;
+	else if ( strcasecmp(method, "HEAD") == 0 )
+		return HTTP_HEAD;
 	else
 		return HTTP_GET;
 }
@@ -604,10 +607,13 @@ Datum http_request(PG_FUNCTION_ARGS)
 	/* Set the HTTP content encoding to gzip */
 	/*curl_easy_setopt(g_http_handle, CURLOPT_ACCEPT_ENCODING, HTTP_ENCODING);*/
 
-	/* Follow redirects, as many as 5 */
-	CURL_SETOPT(g_http_handle, CURLOPT_FOLLOWLOCATION, 1);
-	CURL_SETOPT(g_http_handle, CURLOPT_MAXREDIRS, 5);
-
+	if ( method != HTTP_HEAD )
+	{
+		/* Follow redirects, as many as 5 */
+		CURL_SETOPT(g_http_handle, CURLOPT_FOLLOWLOCATION, 1);
+		CURL_SETOPT(g_http_handle, CURLOPT_MAXREDIRS, 5);
+	}
+
 	if ( g_use_keepalive )
 	{
 		/* Add a keep alive option to the headers to reuse network sockets */
@@ -678,6 +684,10 @@ Datum http_request(PG_FUNCTION_ARGS)
 	{
 		CURL_SETOPT(g_http_handle, CURLOPT_CUSTOMREQUEST, "DELETE");
 	}
+	else if ( method == HTTP_HEAD )
+	{
+		CURL_SETOPT(g_http_handle, CURLOPT_NOBODY, 1);
+	}
 
 	/* Set the headers */
 	CURL_SETOPT(g_http_handle, CURLOPT_HTTPHEADER, headers);

http.control

@@ -1,4 +1,4 @@
-default_version = '1.1'
+default_version = '1.2'
 module_pathname = '$libdir/http'
 relocatable = true
 comment = 'HTTP client for PostgreSQL, allows web page retrieval inside the database.'