[sql] add uri_encode()/uri_decode() functions

Fixes #1014

src/internals/sql-ref.rst

@@ -3624,6 +3624,54 @@ upper(*str*)
 ----
 
 
+.. _uri_decode:
+
+uri_decode(*str*)
+^^^^^^^^^^^^^^^^^
+
+  Decode the given URI-encoded string
+
+  **Parameters**
+    * **str\*** --- The string to decode
+
+  **Examples**
+    To decode '%63%75%72%6c':
+
+    .. code-block::  custsqlite
+
+      ;SELECT uri_decode('%63%75%72%6c')
+      curl
+
+  **See Also**
+    :ref:`uri_encode`
+
+----
+
+
+.. _uri_encode:
+
+uri_encode(*str*)
+^^^^^^^^^^^^^^^^^
+
+  URI-encode the given string
+
+  **Parameters**
+    * **str\*** --- The string to URI-encode
+
+  **Examples**
+    To encode 'Hello, World!':
+
+    .. code-block::  custsqlite
+
+      ;SELECT uri_encode('Hello, World!')
+      Hello%2C%20World%21
+
+  **See Also**
+    :ref:`uri_decode`
+
+----
+
+
 .. _xpath:
 
 xpath(*xpath*, *xmldoc*)

src/network-extension-functions.cc

@@ -41,6 +41,10 @@
 #include "sqlite3.h"
 #include "vtab_module.hh"
 
+#if defined(HAVE_LIBCURL)
+#    include <curl/curl.h>
+#endif
+
 static std::string
 sql_gethostbyname(const char* name_in)
 {
@@ -54,7 +58,8 @@ sql_gethostbyname(const char* name_in)
     for (auto family : {AF_INET, AF_INET6}) {
         hints.ai_family = family;
         while ((rc = getaddrinfo(name_in, nullptr, &hints, ai.out()))
-               == EAI_AGAIN) {
+               == EAI_AGAIN)
+        {
             sqlite3_sleep(10);
         }
         if (rc != 0) {
@@ -130,6 +135,42 @@ sql_gethostbyaddr(const char* addr_str)
     return buffer;
 }
 
+#if defined(HAVE_LIBCURL)
+
+static CURL*
+get_curl_easy()
+{
+    static struct curl_wrapper {
+        curl_wrapper() { this->cw_value = curl_easy_init(); }
+
+        auto_mem<CURL> cw_value{curl_easy_cleanup};
+    } retval;
+
+    return retval.cw_value.in();
+}
+
+static auto_mem<char>
+sql_uri_encode(string_fragment str)
+{
+    auto_mem<char> retval(curl_free);
+
+    retval = curl_easy_escape(get_curl_easy(), str.data(), str.length());
+
+    return retval;
+}
+
+static auto_mem<char>
+sql_uri_decode(string_fragment str)
+{
+    auto_mem<char> retval(curl_free);
+
+    retval = curl_easy_unescape(
+        get_curl_easy(), str.data(), str.length(), nullptr);
+
+    return retval;
+}
+#endif
+
 int
 network_extension_functions(struct FuncDef** basic_funcs,
                             struct FuncDefAgg** agg_funcs)
@@ -159,6 +200,28 @@ network_extension_functions(struct FuncDef** basic_funcs,
                         "SELECT gethostbyaddr('127.0.0.1')",
                     })),
 
+#if defined(HAVE_LIBCURL)
+        sqlite_func_adapter<decltype(&sql_uri_encode), sql_uri_encode>::builder(
+            help_text("uri_encode", "URI-encode the given string")
+                .sql_function()
+                .with_parameter({"str", "The string to URI-encode"})
+                .with_tags({"uri"})
+                .with_example({
+                    "To encode 'Hello, World!'",
+                    "SELECT uri_encode('Hello, World!')",
+                })),
+
+        sqlite_func_adapter<decltype(&sql_uri_decode), sql_uri_decode>::builder(
+            help_text("uri_decode", "Decode the given URI-encoded string")
+                .sql_function()
+                .with_parameter({"str", "The string to decode"})
+                .with_tags({"uri"})
+                .with_example({
+                    "To decode '%63%75%72%6c'",
+                    "SELECT uri_decode('%63%75%72%6c')",
+                })),
+#endif
+
         {nullptr},
     };
 

src/vtab_module.hh

@@ -288,6 +288,13 @@ to_sqlite(sqlite3_context* ctx, double val)
     sqlite3_result_double(ctx, val);
 }
 
+inline void
+to_sqlite(sqlite3_context* ctx, auto_mem<char> str)
+{
+    auto free_func = str.get_free_func<void(*)(void*)>();
+    sqlite3_result_text(ctx, str.release(), -1, free_func);
+}
+
 #define JSON_SUBTYPE    74 /* Ascii for "J" */
 #define FLATTEN_SUBTYPE 0x5f
 

test/expected/test_cmds.sh_b6a3bb78e9d60e5e1f5ce5b18e40d2f1662707ab.out

@@ -4027,6 +4027,32 @@ lnav@googlegroups.com[1] support@lnav.org[2]
    
 
 
+uri_decode(str)
+══════════════════════════════════════════════════════════════════════
+  Decode the given URI-encoded string
+Parameter
+  str   The string to decode
+See Also
+  uri_encode()
+Example
+#1 To decode '%63%75%72%6c':
+   ;SELECT uri_decode('%63%75%72%6c')                 
+   
+
+
+uri_encode(str)
+══════════════════════════════════════════════════════════════════════
+  URI-encode the given string
+Parameter
+  str   The string to URI-encode
+See Also
+  uri_decode()
+Example
+#1 To encode 'Hello, World!':
+   ;SELECT uri_encode('Hello, World!')                
+   
+
+
 xpath(xpath, xmldoc)
 ══════════════════════════════════════════════════════════════════════
   A table-valued function that executes an xpath expression over an