feat(http): add function url_decode and http_get_param_str

plugins/restful/http.c

@@ -56,6 +56,26 @@ static int response(nng_aio *aio, char *content, enum nng_http_status status)
     return 0;
 }
 
+ssize_t url_decode(const char *s, size_t len, char *buf, size_t size)
+{
+    size_t i = 0, j = 0;
+    int    c = 0, n = 0;
+    while (i < len && j < size) {
+        c = s[i++];
+        if ('+' == c) {
+            c = ' ';
+        } else if ('%' == c) {
+            if (i + 2 > len || !sscanf(s + i, "%2x%n", &c, &n) || 2 != n) {
+                return -1;
+            }
+            i += 2, n = 0;
+        }
+        buf[j++] = c;
+    }
+    buf[(j < size) ? j : --j] = '\0';
+    return j;
+}
+
 const char *http_get_header(nng_aio *aio, char *name)
 {
     nng_http_req *req = nng_aio_get_input(aio, 0);
@@ -153,6 +173,17 @@ const char *http_get_param(nng_aio *aio, const char *name, size_t *len)
     return val;
 }
 
+ssize_t http_get_param_str(nng_aio *aio, const char *name, char *buf,
+                           size_t size)
+{
+    size_t      len = 0;
+    const char *s   = http_get_param(aio, name, &len);
+    if (NULL == s) {
+        return -2;
+    }
+    return url_decode(s, len, buf, size);
+}
+
 int http_get_param_uintmax(nng_aio *aio, const char *name, uintmax_t *param)
 {
     size_t      len    = 0;

plugins/restful/http.h

@@ -29,6 +29,12 @@
 extern "C" {
 #endif
 
+// Decode url encoded string.
+// Return -1 if decode fails, otherwise return the number of bytes written to
+// `buf` excluding the terminating NULL byte. A return value of `size` indicates
+// buffer overflow.
+ssize_t url_decode(const char *s, size_t len, char *buf, size_t size);
+
 int http_get_body(nng_aio *aio, void **data, size_t *data_size);
 
 // Find query parameter value of the given name.
@@ -47,6 +53,13 @@ int http_get_body(nng_aio *aio, void **data, size_t *data_size);
 //    touch len.
 const char *http_get_param(nng_aio *aio, const char *name, size_t *len);
 
+// Get query parameter as url decoded string.
+// Return -2 if param does not exist, -1 if url decode fail, otherwise return
+// the number of bytes written to `buf` excluding the terminating NULL byte. A
+// return value of `size` indicates buffer overflow.
+ssize_t http_get_param_str(nng_aio *aio, const char *name, char *buf,
+                           size_t size);
+
 // Returns 0 on success.
 // On failure returns
 //    NEU_ERR_ENOENT if no query parameter named `name`.

tests/http_test.cc

@@ -69,6 +69,43 @@ TEST(HTTPTest, http_get_param)
     nng_url_free(url);
 }
 
+TEST(HTTPTest, http_get_param_str)
+{
+    nng_aio *     aio = NULL;
+    nng_http_req *req = NULL;
+    nng_url *     url = NULL;
+    ssize_t       ret = 0;
+
+    char buf[256] = { 0 };
+    nng_aio_alloc(&aio, NULL, NULL);
+    nng_url_parse(&url, "http://127.0.0.1");
+    nng_http_req_alloc(&req, url);
+    nng_aio_set_input(aio, 0, req);
+
+    nng_http_req_set_uri(req, "/?node_id");
+    ret = http_get_param_str(aio, "group", buf, sizeof(buf));
+    EXPECT_EQ(ret, -2);
+
+    nng_http_req_set_uri(req, "/?group");
+    ret = http_get_param_str(aio, "group", buf, sizeof(buf));
+    EXPECT_EQ(ret, 0);
+    EXPECT_EQ(0, strcmp("", buf));
+
+    nng_http_req_set_uri(req, "/?group=%EZ%BB%84");
+    ret = http_get_param_str(aio, "group", buf, 3);
+    EXPECT_EQ(ret, -1);
+    EXPECT_EQ(0, strcmp("", buf));
+
+    nng_http_req_set_uri(req, "/?group=%E7%BB%84");
+    ret = http_get_param_str(aio, "group", buf, 4);
+    EXPECT_EQ(ret, 3);
+    EXPECT_EQ(0, strcmp("组", buf));
+
+    nng_aio_free(aio);
+    nng_http_req_free(req);
+    nng_url_free(url);
+}
+
 TEST(HTTPTest, http_get_param_node_id)
 {
     nng_aio *     aio     = NULL;