nghtpx: Add BlockAllocator version of base64

src/base64.h

@@ -29,6 +29,9 @@
 
 #include <string>
 
+#include "template.h"
+#include "allocator.h"
+
 namespace nghttp2 {
 
 namespace base64 {
@@ -87,7 +90,8 @@ InputIt next_decode_input(InputIt first, InputIt last, const int *tbl) {
   return first;
 }
 
-template <typename InputIt> std::string decode(InputIt first, InputIt last) {
+template <typename InputIt, typename OutputIt>
+OutputIt decode(InputIt first, InputIt last, OutputIt d_first) {
   static constexpr int INDEX_TABLE[] = {
       -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
       -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
@@ -104,37 +108,29 @@ template <typename InputIt> std::string decode(InputIt first, InputIt last) {
       -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
       -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
       -1, -1, -1, -1};
-  auto len = last - first;
-  if (len % 4 != 0) {
-    return "";
-  }
-  std::string res;
-  res.resize(len / 4 * 3);
 
-  auto p = std::begin(res);
+  auto p = d_first;
   for (; first != last;) {
     uint32_t n = 0;
     for (int i = 1; i <= 4; ++i, ++first) {
       auto idx = INDEX_TABLE[static_cast<size_t>(*first)];
       if (idx == -1) {
         if (i <= 2) {
-          return "";
+          return d_first;
         }
         if (i == 3) {
           if (*first == '=' && *(first + 1) == '=' && first + 2 == last) {
             *p++ = n >> 16;
-            res.resize(p - std::begin(res));
-            return res;
+            return p;
           }
-          return "";
+          return d_first;
         }
         if (*first == '=' && first + 1 == last) {
           *p++ = n >> 16;
           *p++ = n >> 8 & 0xffu;
-          res.resize(p - std::begin(res));
-          return res;
+          return p;
         }
-        return "";
+        return d_first;
       }
 
       n += idx << (24 - i * 6);
@@ -145,9 +141,37 @@ template <typename InputIt> std::string decode(InputIt first, InputIt last) {
     *p++ = n & 0xffu;
   }
 
+  return p;
+}
+
+template <typename InputIt> std::string decode(InputIt first, InputIt last) {
+  auto len = std::distance(first, last);
+  if (len % 4 != 0) {
+    return "";
+  }
+  std::string res;
+  res.resize(len / 4 * 3);
+
+  res.erase(decode(first, last, std::begin(res)), std::end(res));
+
   return res;
 }
 
+template <typename InputIt>
+StringRef decode(BlockAllocator &balloc, InputIt first, InputIt last) {
+  auto len = std::distance(first, last);
+  if (len % 4 != 0) {
+    return StringRef::from_lit("");
+  }
+  auto iov = make_byte_ref(balloc, len / 4 * 3 + 1);
+  auto p = iov.base;
+
+  p = decode(first, last, p);
+  *p = '\0';
+
+  return StringRef{iov.base, p};
+}
+
 } // namespace base64
 
 } // namespace nghttp2

src/base64_test.cc

@@ -59,31 +59,40 @@ void test_base64_encode(void) {
 }
 
 void test_base64_decode(void) {
+  BlockAllocator balloc(4096, 4096);
   {
     std::string in = "/w==";
     auto out = base64::decode(std::begin(in), std::end(in));
     CU_ASSERT("\xff" == out);
+    CU_ASSERT("\xff" == base64::decode(balloc, std::begin(in), std::end(in)));
   }
   {
     std::string in = "//4=";
     auto out = base64::decode(std::begin(in), std::end(in));
     CU_ASSERT("\xff\xfe" == out);
+    CU_ASSERT("\xff\xfe" ==
+              base64::decode(balloc, std::begin(in), std::end(in)));
   }
   {
     std::string in = "//79";
     auto out = base64::decode(std::begin(in), std::end(in));
     CU_ASSERT("\xff\xfe\xfd" == out);
+    CU_ASSERT("\xff\xfe\xfd" ==
+              base64::decode(balloc, std::begin(in), std::end(in)));
   }
   {
     std::string in = "//79/A==";
     auto out = base64::decode(std::begin(in), std::end(in));
     CU_ASSERT("\xff\xfe\xfd\xfc" == out);
+    CU_ASSERT("\xff\xfe\xfd\xfc" ==
+              base64::decode(balloc, std::begin(in), std::end(in)));
   }
   {
     // we check the number of valid input must be multiples of 4
     std::string in = "//79=";
     auto out = base64::decode(std::begin(in), std::end(in));
     CU_ASSERT("" == out);
+    CU_ASSERT("" == base64::decode(balloc, std::begin(in), std::end(in)));
   }
   {
     // ending invalid character at the boundary of multiples of 4 is
@@ -91,18 +100,21 @@ void test_base64_decode(void) {
     std::string in = "bmdodHRw\n";
     auto out = base64::decode(std::begin(in), std::end(in));
     CU_ASSERT("" == out);
+    CU_ASSERT("" == base64::decode(balloc, std::begin(in), std::end(in)));
   }
   {
     // after seeing '=', subsequent input must be also '='.
     std::string in = "//79/A=A";
     auto out = base64::decode(std::begin(in), std::end(in));
     CU_ASSERT("" == out);
+    CU_ASSERT("" == base64::decode(balloc, std::begin(in), std::end(in)));
   }
   {
     // additional '=' at the end is bad
     std::string in = "//79/A======";
     auto out = base64::decode(std::begin(in), std::end(in));
     CU_ASSERT("" == out);
+    CU_ASSERT("" == base64::decode(balloc, std::begin(in), std::end(in)));
   }
 }
 

src/shrpx_http2_upstream.cc

@@ -108,15 +108,16 @@ int on_stream_close_callback(nghttp2_session *session, int32_t stream_id,
 int Http2Upstream::upgrade_upstream(HttpsUpstream *http) {
   int rv;
 
-  auto http2_settings = http->get_downstream()->get_http2_settings().str();
-  util::to_base64(http2_settings);
+  auto &balloc = http->get_downstream()->get_block_allocator();
 
-  auto settings_payload =
-      base64::decode(std::begin(http2_settings), std::end(http2_settings));
+  auto http2_settings = http->get_downstream()->get_http2_settings();
+  http2_settings = util::to_base64(balloc, http2_settings);
+
+  auto settings_payload = base64::decode(balloc, std::begin(http2_settings),
+                                         std::end(http2_settings));
 
   rv = nghttp2_session_upgrade2(
-      session_, reinterpret_cast<const uint8_t *>(settings_payload.c_str()),
-      settings_payload.size(),
+      session_, settings_payload.byte(), settings_payload.size(),
       http->get_downstream()->request().method == HTTP_HEAD, nullptr);
   if (rv != 0) {
     if (LOG_ENABLED(INFO)) {

src/util.cc

@@ -410,22 +410,32 @@ void to_token68(std::string &base64str) {
                   std::end(base64str));
 }
 
-void to_base64(std::string &token68str) {
-  std::transform(std::begin(token68str), std::end(token68str),
-                 std::begin(token68str), [](char c) {
-                   switch (c) {
-                   case '-':
-                     return '+';
-                   case '_':
-                     return '/';
-                   default:
-                     return c;
-                   }
-                 });
-  if (token68str.size() & 0x3) {
-    token68str.append(4 - (token68str.size() & 0x3), '=');
+StringRef to_base64(BlockAllocator &balloc, const StringRef &token68str) {
+  // At most 3 padding '='
+  auto len = token68str.size() + 3;
+  auto iov = make_byte_ref(balloc, len + 1);
+  auto p = iov.base;
+
+  p = std::transform(std::begin(token68str), std::end(token68str), p,
+                     [](char c) {
+                       switch (c) {
+                       case '-':
+                         return '+';
+                       case '_':
+                         return '/';
+                       default:
+                         return c;
+                       }
+                     });
+
+  auto rem = token68str.size() & 0x3;
+  if (rem) {
+    p = std::fill_n(p, 4 - rem, '=');
   }
-  return;
+
+  *p = '\0';
+
+  return StringRef{iov.base, p};
 }
 
 namespace {

src/util.h

@@ -426,7 +426,8 @@ template <typename T> std::string utox(T n) {
 }
 
 void to_token68(std::string &base64str);
-void to_base64(std::string &token68str);
+
+StringRef to_base64(BlockAllocator &balloc, const StringRef &token68str);
 
 void show_candidates(const char *unkopt, option *options);
 

src/util_test.cc

@@ -114,13 +114,12 @@ void test_util_inp_strlower(void) {
 }
 
 void test_util_to_base64(void) {
-  std::string x = "AAA--B_";
-  util::to_base64(x);
-  CU_ASSERT("AAA++B/=" == x);
+  BlockAllocator balloc(4096, 4096);
 
-  x = "AAA--B_B";
-  util::to_base64(x);
-  CU_ASSERT("AAA++B/B" == x);
+  CU_ASSERT("AAA++B/=" ==
+            util::to_base64(balloc, StringRef::from_lit("AAA--B_")));
+  CU_ASSERT("AAA++B/B" ==
+            util::to_base64(balloc, StringRef::from_lit("AAA--B_B")));
 }
 
 void test_util_to_token68(void) {