From 6b78da6f02dd2859f047456a98c6bfd8a31cfc1d Mon Sep 17 00:00:00 2001
From: zzsmdfj <zzsmdfj@gmail.com>
Date: Thu, 17 Feb 2022 11:32:47 +0800
Subject: [PATCH] to issue/#31092_add_encodeURLComponent_function

---
 src/Functions/URL/decodeURLComponent.cpp | 29 ++++++++++++++++--------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/src/Functions/URL/decodeURLComponent.cpp b/src/Functions/URL/decodeURLComponent.cpp
index 5fff9c2920a..64f117708c8 100644
--- a/src/Functions/URL/decodeURLComponent.cpp
+++ b/src/Functions/URL/decodeURLComponent.cpp
@@ -17,7 +17,7 @@ static size_t encodeURL(const char * src, size_t src_size, char * dst, bool spac
     for (size_t i = 0; i < src_size - 1; i++)
     {
         if ((src[i] >= '0' && src[i] <= '9') || (src[i] >= 'a' && src[i] <= 'z') || (src[i] >= 'A' && src[i] <= 'Z')
-            || src[i] == '-' || src[i] == '_' || src[i] == '.' || src[i] == '!' || src[i] == '~' || (src[i] >= '\'' && src[i] <= '*'))
+            || src[i] == '-' || src[i] == '_' || src[i] == '.' || src[i] == '~')
         {
             *dst_pos++ = src[i];
         }
@@ -106,15 +106,24 @@ static size_t decodeURL(const char * src, size_t src_size, char * dst, bool plus
     return dst_pos - dst;
 }
 
+enum URLCodeStrategy
+{
+    encode,
+    decode
+};
 
 /// Percent decode of URL data.
-template <bool plus_as_space, bool encode>
+template <bool plus_space_swap, URLCodeStrategy code_strategy>
 struct CodeURLComponentImpl
 {
     static void vector(const ColumnString::Chars & data, const ColumnString::Offsets & offsets,
         ColumnString::Chars & res_data, ColumnString::Offsets & res_offsets)
     {
-        res_data.resize(data.size());
+        if (code_strategy == encode)
+            //the destination(res_data) string is at most three times the length of the source string
+            res_data.resize(data.size() * 3);
+        else
+            res_data.resize(data.size());
         size_t size = offsets.size();
         res_offsets.resize(size);
 
@@ -126,10 +135,10 @@ struct CodeURLComponentImpl
             const char * src_data = reinterpret_cast<const char *>(&data[prev_offset]);
             size_t src_size = offsets[i] - prev_offset;
             size_t dst_size;
-            if (encode)
-                dst_size = encodeURL(src_data, src_size, reinterpret_cast<char *>(res_data.data() + res_offset), plus_as_space);
+            if (code_strategy == encode)
+                dst_size = encodeURL(src_data, src_size, reinterpret_cast<char *>(res_data.data() + res_offset), plus_space_swap);
             else
-                dst_size = decodeURL(src_data, src_size, reinterpret_cast<char *>(res_data.data() + res_offset), plus_as_space);
+                dst_size = decodeURL(src_data, src_size, reinterpret_cast<char *>(res_data.data() + res_offset), plus_space_swap);
             res_offset += dst_size;
             res_offsets[i] = res_offset;
             prev_offset = offsets[i];
@@ -149,10 +158,10 @@ struct NameDecodeURLComponent { static constexpr auto name = "decodeURLComponent
 struct NameEncodeURLComponent { static constexpr auto name = "encodeURLComponent"; };
 struct NameDecodeURLFormComponent { static constexpr auto name = "decodeURLFormComponent"; };
 struct NameEncodeURLFormComponent { static constexpr auto name = "encodeURLFormComponent"; };
-using FunctionDecodeURLComponent = FunctionStringToString<CodeURLComponentImpl<false, false>, NameDecodeURLComponent>;
-using FunctionEncodeURLComponent = FunctionStringToString<CodeURLComponentImpl<false, true>, NameEncodeURLComponent>;
-using FunctionDecodeURLFormComponent = FunctionStringToString<CodeURLComponentImpl<true, false>, NameDecodeURLFormComponent>;
-using FunctionEncodeURLFormComponent = FunctionStringToString<CodeURLComponentImpl<true, true>, NameEncodeURLFormComponent>;
+using FunctionDecodeURLComponent = FunctionStringToString<CodeURLComponentImpl<false, decode>, NameDecodeURLComponent>;
+using FunctionEncodeURLComponent = FunctionStringToString<CodeURLComponentImpl<false, encode>, NameEncodeURLComponent>;
+using FunctionDecodeURLFormComponent = FunctionStringToString<CodeURLComponentImpl<true, decode>, NameDecodeURLFormComponent>;
+using FunctionEncodeURLFormComponent = FunctionStringToString<CodeURLComponentImpl<true, encode>, NameEncodeURLFormComponent>;
 
 void registerFunctionEncodeAndDecodeURLComponent(FunctionFactory & factory)
 {