From 8eb0a830da652b035cdc7e8a728fada8cb9b54af Mon Sep 17 00:00:00 2001
From: Paul Bissonnette <paulbiss@fb.com>
Date: Mon, 19 Aug 2013 00:35:18 -0700
Subject: [PATCH] Updating ext_string for benchmark optimizations

String optimizations, this gives us a 40% reduction in cycles for the revcomp benchmark.

Differential Revision: D934224
---
 hphp/runtime/base/array-util.cpp              |   5 +-
 hphp/runtime/base/builtin-functions.cpp       |   5 +-
 hphp/runtime/base/stream-wrapper-registry.cpp |  10 +-
 hphp/runtime/base/string-util.cpp             | 163 ------
 hphp/runtime/base/string-util.h               |  34 --
 hphp/runtime/debugger/cmd/cmd_info.cpp        |   3 +-
 hphp/runtime/debugger/debugger_client.cpp     |  19 +-
 hphp/runtime/ext/ext_domdocument.cpp          |   3 +-
 hphp/runtime/ext/ext_hash.cpp                 |   7 +-
 hphp/runtime/ext/ext_mb.cpp                   |   5 +-
 hphp/runtime/ext/ext_pdo.cpp                  |   5 +-
 hphp/runtime/ext/ext_process.cpp              |   7 +-
 hphp/runtime/ext/ext_reflection.cpp           |   7 +-
 hphp/runtime/ext/ext_soap.cpp                 |   7 +-
 hphp/runtime/ext/ext_spl.cpp                  |   3 +-
 hphp/runtime/ext/ext_string.cpp               | 519 +++++++++++++++++-
 hphp/runtime/ext/soap/encoding.cpp            |   5 +-
 hphp/runtime/server/http-protocol.cpp         |   5 +-
 .../server/libevent-server-with-takeover.cpp  |   5 +-
 hphp/test/ext/test_cpp_base.cpp               |   3 +-
 hphp/test/quick/string-util.php               |  27 +
 hphp/test/quick/string-util.php.expect        |  10 +
 22 files changed, 591 insertions(+), 266 deletions(-)
 create mode 100644 hphp/test/quick/string-util.php
 create mode 100644 hphp/test/quick/string-util.php.expect

diff --git a/hphp/runtime/base/array-util.cpp b/hphp/runtime/base/array-util.cpp
index 7d31d7eb3..8ed04e5b9 100644
--- a/hphp/runtime/base/array-util.cpp
+++ b/hphp/runtime/base/array-util.cpp
@@ -21,6 +21,7 @@
 #include "hphp/runtime/base/runtime-error.h"
 #include "hphp/runtime/ext/ext_math.h"
 #include "hphp/runtime/ext/ext_json.h"
+#include "hphp/runtime/ext/ext_string.h"
 
 namespace HPHP {
 ///////////////////////////////////////////////////////////////////////////////
@@ -479,9 +480,9 @@ Variant ArrayUtil::ChangeKeyCase(CArrRef input, bool lower) {
     Variant key(iter.first());
     if (key.isString()) {
       if (lower) {
-        ret.set(StringUtil::ToLower(key.toString()), iter.secondRef());
+        ret.set(f_strtolower(key.toString()), iter.secondRef());
       } else {
-        ret.set(StringUtil::ToUpper(key.toString()), iter.secondRef());
+        ret.set(f_strtoupper(key.toString()), iter.secondRef());
       }
     } else {
       ret.set(key, iter.secondRef());
diff --git a/hphp/runtime/base/builtin-functions.cpp b/hphp/runtime/base/builtin-functions.cpp
index 7b932dc20..a2c4d4908 100644
--- a/hphp/runtime/base/builtin-functions.cpp
+++ b/hphp/runtime/base/builtin-functions.cpp
@@ -31,6 +31,7 @@
 #include "hphp/runtime/ext/ext_function.h"
 #include "hphp/runtime/ext/ext_file.h"
 #include "hphp/runtime/ext/ext_collections.h"
+#include "hphp/runtime/ext/ext_string.h"
 #include "hphp/util/logger.h"
 #include "hphp/util/util.h"
 #include "hphp/util/process.h"
@@ -1057,7 +1058,7 @@ AutoloadHandler::Result AutoloadHandler::loadFromMap(CStrRef name,
     CVarRef &type_map = m_map.get()->get(kind);
     auto const typeMapCell = type_map.asCell();
     if (typeMapCell->m_type != KindOfArray) return Failure;
-    String canonicalName = toLower ? StringUtil::ToLower(name) : name;
+    String canonicalName = toLower ? f_strtolower(name) : name;
     CVarRef &file = typeMapCell->m_data.parr->get(canonicalName);
     bool ok = false;
     if (file.isString()) {
@@ -1222,7 +1223,7 @@ String AutoloadHandler::getSignature(CVarRef handler) {
   if (!f_is_callable(handler, false, ref(name))) {
     return null_string;
   }
-  String lName = StringUtil::ToLower(name.toString());
+  String lName = f_strtolower(name.toString());
   if (handler.isArray()) {
     Variant first = handler.getArrayData()->get(int64_t(0));
     if (first.isObject()) {
diff --git a/hphp/runtime/base/stream-wrapper-registry.cpp b/hphp/runtime/base/stream-wrapper-registry.cpp
index 03e5fc2df..a7ab5e39c 100644
--- a/hphp/runtime/base/stream-wrapper-registry.cpp
+++ b/hphp/runtime/base/stream-wrapper-registry.cpp
@@ -16,11 +16,11 @@
 
 #include "hphp/runtime/base/stream-wrapper-registry.h"
 #include "hphp/runtime/base/file.h"
-#include "hphp/runtime/base/string-util.h"
 #include "hphp/runtime/base/file-stream-wrapper.h"
 #include "hphp/runtime/base/php-stream-wrapper.h"
 #include "hphp/runtime/base/http-stream-wrapper.h"
 #include "hphp/runtime/base/request-local.h"
+#include "hphp/runtime/ext/ext_string.h"
 #include <set>
 #include <map>
 
@@ -60,7 +60,7 @@ const StaticString
   s_compress_zlib("compress.zlib");
 
 bool disableWrapper(CStrRef scheme) {
-  String lscheme = StringUtil::ToLower(scheme);
+  String lscheme = f_strtolower(scheme);
 
   if (lscheme.same(s_file)) {
     // Zend quietly succeeds, but does nothing
@@ -94,7 +94,7 @@ bool disableWrapper(CStrRef scheme) {
 }
 
 bool restoreWrapper(CStrRef scheme) {
-  String lscheme = StringUtil::ToLower(scheme);
+  String lscheme = f_strtolower(scheme);
   bool ret = false;
 
   // Unregister request-specific wrapper
@@ -117,7 +117,7 @@ bool restoreWrapper(CStrRef scheme) {
 }
 
 bool registerRequestWrapper(CStrRef scheme, std::unique_ptr<Wrapper> wrapper) {
-  String lscheme = StringUtil::ToLower(scheme);
+  String lscheme = f_strtolower(scheme);
 
   // Global, non-disabled wrapper
   if ((s_wrappers.find(lscheme.data()) != s_wrappers.end()) &&
@@ -156,7 +156,7 @@ Array enumWrappers() {
 }
 
 Wrapper* getWrapper(CStrRef scheme) {
-  String lscheme = StringUtil::ToLower(scheme);
+  String lscheme = f_strtolower(scheme);
 
   // Request local wrapper?
   {
diff --git a/hphp/runtime/base/string-util.cpp b/hphp/runtime/base/string-util.cpp
index 14fca8d4b..dd6db51cb 100644
--- a/hphp/runtime/base/string-util.cpp
+++ b/hphp/runtime/base/string-util.cpp
@@ -26,65 +26,6 @@ namespace HPHP {
 ///////////////////////////////////////////////////////////////////////////////
 // manipulations
 
-String StringUtil::ToLower(CStrRef input,
-                           ToLowerType type /*= ToLowerType::All */) {
-  if (input.empty()) return input;
-
-  int len = input.size();
-  char *ret = nullptr;
-  switch (type) {
-  case ToLowerType::All:
-    ret = string_to_lower(input.data(), len);
-    break;
-  case ToLowerType::First:
-    ret = string_to_lower_first(input.data(), len);
-    break;
-  case ToLowerType::Words:
-    ret = string_to_lower_words(input.data(), len);
-    break;
-  default:
-    assert(false);
-    break;
-  }
-  return String(ret, len, AttachString);
-}
-
-String StringUtil::ToUpper(CStrRef input,
-                           ToUpperType type /*= ToUpperType::All */) {
-  if (input.empty()) return input;
-
-  int len = input.size();
-  char *ret = nullptr;
-  switch (type) {
-  case ToUpperType::All:
-    ret = string_to_upper(input.data(), len);
-    break;
-  case ToUpperType::First:
-    ret = string_to_upper_first(input.data(), len);
-    break;
-  case ToUpperType::Words:
-    ret = string_to_upper_words(input.data(), len);
-    break;
-  default:
-    assert(false);
-    break;
-  }
-  return String(ret, len, AttachString);
-}
-
-String StringUtil::Trim(CStrRef input, TrimType type  /* = TrimType::Both */,
-                        CStrRef charlist /* = k_HPHP_TRIM_CHARLIST */) {
-  if (input.empty()) return input;
-  int len = input.size();
-  char *ret = string_trim(input.data(), len,
-                          charlist.data(), charlist.length(),
-                          static_cast<int>(type));
-  if (!ret) {
-      return input;
-  }
-  return String(ret, len, AttachString);
-}
-
 String StringUtil::Pad(CStrRef input, int final_length,
                        CStrRef pad_string /* = " " */,
                        PadType type /* = PadType::Right */) {
@@ -95,41 +36,6 @@ String StringUtil::Pad(CStrRef input, int final_length,
   return String();
 }
 
-String StringUtil::Reverse(CStrRef input) {
-  if (input.empty()) return input;
-  int len = input.size();
-  return String(string_reverse(input.data(), len), len, AttachString);
-}
-
-String StringUtil::Repeat(CStrRef input, int count) {
-  if (count < 0) {
-    raise_warning("Second argument has to be greater than or equal to 0");
-    return String();
-  }
-  if (count == 0) {
-    return "";
-  }
-  if (!input.empty()) {
-    int len = input.size();
-    char *ret = string_repeat(input.data(), len, count);
-    if (ret) {
-      return String(ret, len, AttachString);
-    }
-  }
-  return input;
-}
-
-String StringUtil::Shuffle(CStrRef input) {
-  if (!input.empty()) {
-    int len = input.size();
-    char *ret = string_shuffle(input.data(), len);
-    if (ret) {
-      return String(ret, len, AttachString);
-    }
-  }
-  return input;
-}
-
 String StringUtil::StripHTMLTags(CStrRef input,
                                  CStrRef allowable_tags /* = "" */) {
   if (input.empty()) return input;
@@ -139,21 +45,6 @@ String StringUtil::StripHTMLTags(CStrRef input,
   return String(ret, len, AttachString);
 }
 
-String StringUtil::WordWrap(CStrRef input, int width,
-                            CStrRef wordbreak /* = "\n" */,
-                            bool cut /* = false */) {
-  if (!input.empty()) {
-    int len = input.size();
-    char *ret = string_wordwrap(input.data(), len, width, wordbreak.data(),
-                                wordbreak.size(), cut);
-    if (ret) {
-      return String(ret, len, AttachString);
-    }
-    return String();
-  }
-  return input;
-}
-
 ///////////////////////////////////////////////////////////////////////////////
 // splits/joins
 
@@ -303,46 +194,6 @@ Variant StringUtil::ChunkSplit(CStrRef body, int chunklen /* = 76 */,
 ///////////////////////////////////////////////////////////////////////////////
 // encoding/decoding
 
-String StringUtil::CEncode(CStrRef input, CStrRef charlist) {
-  String chars = charlist;
-  if (chars.isNull()) {
-    chars = String("\\\x00\x01..\x1f\x7f..\xff", 10, CopyString);
-  }
-  if (input.empty() || chars.empty()) return input;
-  int len = input.size();
-  char *ret = string_addcslashes(input.c_str(), len, chars.data(),
-                                 chars.size());
-  return String(ret, len, AttachString);
-}
-
-String StringUtil::CDecode(CStrRef input) {
-  if (input.empty()) return input;
-  int len = input.size();
-  char *ret = string_stripcslashes(input.c_str(), len);
-  return String(ret, len, AttachString);
-}
-
-String StringUtil::SqlEncode(CStrRef input) {
-  if (input.empty()) return input;
-  int len = input.size();
-  char *ret = string_addslashes(input.c_str(), len);
-  return String(ret, len, AttachString);
-}
-
-String StringUtil::SqlDecode(CStrRef input) {
-  if (input.empty()) return input;
-  int len = input.size();
-  char *ret = string_stripslashes(input.c_str(), len);
-  return String(ret, len, AttachString);
-}
-
-String StringUtil::RegExEncode(CStrRef input) {
-  if (input.empty()) return input;
-  int len = input.size();
-  char *ret = string_quotemeta(input.c_str(), len);
-  return String(ret, len, AttachString);
-}
-
 String StringUtil::HtmlEncode(CStrRef input, QuoteStyle quoteStyle,
                               const char *charset, bool nbsp) {
   if (input.empty()) return input;
@@ -485,20 +336,6 @@ String StringUtil::QuotedPrintableDecode(CStrRef input) {
   return String(ret, len, AttachString);
 }
 
-String StringUtil::HexEncode(CStrRef input) {
-  if (input.empty()) return input;
-  int len = input.size();
-  char *ret = string_bin2hex(input.data(), len);
-  return String(ret, len, AttachString);
-}
-
-String StringUtil::HexDecode(CStrRef input) {
-  if (input.empty()) return input;
-  int len = input.size();
-  char *ret = string_hex2bin(input.data(), len);
-  return String(ret, len, AttachString);
-}
-
 String StringUtil::UUEncode(CStrRef input) {
   if (input.empty()) return input;
 
diff --git a/hphp/runtime/base/string-util.h b/hphp/runtime/base/string-util.h
index 66e2bbbb9..ab48420d1 100644
--- a/hphp/runtime/base/string-util.h
+++ b/hphp/runtime/base/string-util.h
@@ -30,24 +30,6 @@ extern const StaticString k_HPHP_TRIM_CHARLIST;
  */
 class StringUtil {
 public:
-  enum class ToUpperType {
-    All,
-    First,
-    Words
-  };
-
-  enum class ToLowerType {
-    All,
-    First,
-    Words
-  };
-
-  enum class TrimType {
-    Left  = 1,
-    Right = 2,
-    Both  = 3
-  };
-
   enum class PadType {
     Left = 0,
     Right = 1,
@@ -67,18 +49,9 @@ public:
    * Manipulations. Note, all these functions will create a new string than
    * modifying input, although names of these functions sound like mutating.
    */
-  static String ToLower(CStrRef input, ToLowerType type = ToLowerType::All);
-  static String ToUpper(CStrRef input, ToUpperType type = ToUpperType::All);
-  static String Trim(CStrRef input, TrimType type = TrimType::Both,
-                     CStrRef charlist = k_HPHP_TRIM_CHARLIST);
   static String Pad(CStrRef input, int final_length,
                     CStrRef pad_string = " ", PadType type = PadType::Right);
-  static String Reverse(CStrRef input);
-  static String Repeat(CStrRef input, int count);
-  static String Shuffle(CStrRef input);
   static String StripHTMLTags(CStrRef input, CStrRef allowable_tags = "");
-  static String WordWrap(CStrRef input, int width,
-                         CStrRef wordbreak = "\n", bool cut = false);
 
   /**
    * Split/joins.
@@ -93,11 +66,6 @@ public:
   /**
    * Encoding/decoding.
    */
-  static String CEncode(CStrRef input, CStrRef charlist);
-  static String CDecode(CStrRef input);
-  static String SqlEncode(CStrRef input);
-  static String SqlDecode(CStrRef input);
-  static String RegExEncode(CStrRef input);
   static String HtmlEncode(CStrRef input, QuoteStyle quoteStyle,
                            const char *charset, bool nbsp);
   static String HtmlEncodeExtra(CStrRef input, QuoteStyle quoteStyle,
@@ -106,8 +74,6 @@ public:
                            const char *charset, bool all);
   static String QuotedPrintableEncode(CStrRef input);
   static String QuotedPrintableDecode(CStrRef input);
-  static String HexEncode(CStrRef input);
-  static String HexDecode(CStrRef input);
   static String UUEncode(CStrRef input);
   static String UUDecode(CStrRef input);
   static String Base64Encode(CStrRef input);
diff --git a/hphp/runtime/debugger/cmd/cmd_info.cpp b/hphp/runtime/debugger/cmd/cmd_info.cpp
index 08f4289c6..83982faf5 100644
--- a/hphp/runtime/debugger/cmd/cmd_info.cpp
+++ b/hphp/runtime/debugger/cmd/cmd_info.cpp
@@ -17,6 +17,7 @@
 #include "hphp/runtime/debugger/cmd/cmd_info.h"
 #include "hphp/runtime/debugger/cmd/cmd_variable.h"
 #include "hphp/runtime/ext/ext_reflection.h"
+#include "hphp/runtime/ext/ext_string.h"
 #include "hphp/runtime/base/preg.h"
 #include "hphp/util/logger.h"
 
@@ -292,7 +293,7 @@ void CmdInfo::PrintDocComments(StringBuffer &sb, CArrRef info) {
       space1 = matches1[1].toString().size();
       space2 = matches2[1].toString().size();
     }
-    String spaces = StringUtil::Repeat(" ", space2 - space1 - 1);
+    String spaces = f_str_repeat(" ", space2 - space1 - 1);
     sb.printf("%s%s\n", spaces.data(), doc.data());
   }
 }
diff --git a/hphp/runtime/debugger/debugger_client.cpp b/hphp/runtime/debugger/debugger_client.cpp
index 99821d2ba..37ed96516 100644
--- a/hphp/runtime/debugger/debugger_client.cpp
+++ b/hphp/runtime/debugger/debugger_client.cpp
@@ -24,6 +24,7 @@
 #include "hphp/runtime/ext/ext_json.h"
 #include "hphp/runtime/ext/ext_socket.h"
 #include "hphp/runtime/ext/ext_network.h"
+#include "hphp/runtime/ext/ext_string.h"
 #include "hphp/util/text-color.h"
 #include "hphp/util/text-art.h"
 #include "hphp/util/logger.h"
@@ -384,7 +385,7 @@ String DebuggerClient::FormatInfoVec(const IDebuggable::InfoVec &info,
 
 String DebuggerClient::FormatTitle(const char *title) {
   TRACE(2, "DebuggerClient::FormatTitle\n");
-  String dash = StringUtil::Repeat(BOX_H, (LineWidth - strlen(title)) / 2 - 4);
+  String dash = f_str_repeat(BOX_H, (LineWidth - strlen(title)) / 2 - 4);
 
   StringBuffer sb;
   sb.append("\n");
@@ -1309,7 +1310,7 @@ IMPLEMENT_COLOR_OUTPUT(error,    stderr,  ErrorColor);
 
 string DebuggerClient::wrap(const std::string &s) {
   TRACE(2, "DebuggerClient::wrap\n");
-  String ret = StringUtil::WordWrap(String(s.c_str(), s.size(), CopyString),
+  String ret = f_wordwrap(String(s.c_str(), s.size(), CopyString),
                                     LineWidth - 4, "\n", true);
   return string(ret.data(), ret.size());
 }
@@ -1368,8 +1369,8 @@ void DebuggerClient::helpCmds(const std::vector<const char *> &cmds) {
       continue;
     }
 
-    cmd = StringUtil::WordWrap(cmd, left, "\n", true);
-    desc = StringUtil::WordWrap(desc, right, "\n", true);
+    cmd = f_wordwrap(cmd, left, "\n", true);
+    desc = f_wordwrap(desc, right, "\n", true);
     Array lines1 = StringUtil::Explode(cmd, "\n").toArray();
     Array lines2 = StringUtil::Explode(desc, "\n").toArray();
     for (int n = 0; n < lines1.size() || n < lines2.size(); n++) {
@@ -1381,7 +1382,7 @@ void DebuggerClient::helpCmds(const std::vector<const char *> &cmds) {
       line.append("  ");
       line.append(lines2[n].toString());
 
-      sb.append(StringUtil::Trim(line.detach(), StringUtil::TrimType::Right));
+      sb.append(f_rtrim(line.detach()));
       sb.append("\n");
     }
   }
@@ -1406,20 +1407,20 @@ void DebuggerClient::tutorial(const char *text) {
   if (m_tutorial < 0) return;
 
   String ret = String(text).replace("\t", "    ");
-  ret = StringUtil::WordWrap(ret, LineWidth - 4, "\n", true);
+  ret = f_wordwrap(ret, LineWidth - 4, "\n", true);
   Array lines = StringUtil::Explode(ret, "\n").toArray();
 
   StringBuffer sb;
   String header = "  Tutorial - '[h]elp [t]utorial off|auto' to turn off  ";
-  String hr = StringUtil::Repeat(BOX_H, LineWidth - 2);
+  String hr = f_str_repeat(BOX_H, LineWidth - 2);
 
   sb.append(BOX_UL); sb.append(hr); sb.append(BOX_UR); sb.append("\n");
 
   int wh = (LineWidth - 2 - header.size()) / 2;
   sb.append(BOX_V);
-  sb.append(StringUtil::Repeat(" ", wh));
+  sb.append(f_str_repeat(" ", wh));
   sb.append(header);
-  sb.append(StringUtil::Repeat(" ", wh));
+  sb.append(f_str_repeat(" ", wh));
   sb.append(BOX_V);
   sb.append("\n");
 
diff --git a/hphp/runtime/ext/ext_domdocument.cpp b/hphp/runtime/ext/ext_domdocument.cpp
index 8b71b4510..5308ef500 100644
--- a/hphp/runtime/ext/ext_domdocument.cpp
+++ b/hphp/runtime/ext/ext_domdocument.cpp
@@ -18,6 +18,7 @@
 #include "hphp/runtime/ext/ext_domdocument.h"
 #include "hphp/runtime/ext/ext_file.h"
 #include "hphp/runtime/ext/ext_class.h"
+#include "hphp/runtime/ext/ext_string.h"
 #include "hphp/runtime/base/runtime-error.h"
 #include "hphp/runtime/ext/ext_function.h"
 #include "hphp/runtime/ext/ext_simplexml.h"
@@ -3431,7 +3432,7 @@ bool c_DOMDocument::t_registernodeclass(CStrRef baseclass,
                 baseclass.data());
     return false;
   }
-  m_classmap.set(StringUtil::ToLower(baseclass), extendedclass);
+  m_classmap.set(f_strtolower(baseclass), extendedclass);
   return true;
 }
 
diff --git a/hphp/runtime/ext/ext_hash.cpp b/hphp/runtime/ext/ext_hash.cpp
index 080f00062..5166d32d0 100644
--- a/hphp/runtime/ext/ext_hash.cpp
+++ b/hphp/runtime/ext/ext_hash.cpp
@@ -17,6 +17,7 @@
 
 #include "hphp/runtime/ext/ext_hash.h"
 #include "hphp/runtime/ext/ext_file.h"
+#include "hphp/runtime/ext/ext_string.h"
 #include "hphp/runtime/ext/hash/hash_md.h"
 #include "hphp/runtime/ext/hash/hash_sha.h"
 #include "hphp/runtime/ext/hash/hash_ripemd.h"
@@ -170,7 +171,7 @@ Array HHVM_FUNCTION(hash_algos) {
 
 static HashEnginePtr php_hash_fetch_ops(CStrRef algo) {
   HashEngineMap::const_iterator iter =
-    HashEngines.find(StringUtil::ToLower(algo).data());
+    HashEngines.find(f_strtolower(algo).data());
   if (iter == HashEngines.end()) {
     return HashEnginePtr();
   }
@@ -215,7 +216,7 @@ static Variant php_hash_do_hash(CStrRef algo, CStrRef data, bool isfilename,
   if (raw_output) {
     return raw;
   }
-  return StringUtil::HexEncode(raw);
+  return f_bin2hex(raw);
 }
 
 Variant HHVM_FUNCTION(hash, CStrRef algo, CStrRef data,
@@ -316,7 +317,7 @@ String HHVM_FUNCTION(hash_final, CResRef context,
   if (raw_output) {
     return raw;
   }
-  return StringUtil::HexEncode(raw);
+  return f_bin2hex(raw);
 }
 
 int64_t HHVM_FUNCTION(furchash_hphp_ext, CStrRef key,
diff --git a/hphp/runtime/ext/ext_mb.cpp b/hphp/runtime/ext/ext_mb.cpp
index a79bb0323..b5d6999b8 100644
--- a/hphp/runtime/ext/ext_mb.cpp
+++ b/hphp/runtime/ext/ext_mb.cpp
@@ -21,6 +21,7 @@
 #include "hphp/runtime/ext/php_unicode.h"
 #include "hphp/runtime/ext/unicode_data.h"
 #include "hphp/runtime/ext/ext_process.h"
+#include "hphp/runtime/ext/ext_string.h"
 #include "hphp/runtime/base/zend-url.h"
 #include "hphp/runtime/base/zend-string.h"
 #include "hphp/runtime/base/ini-setting.h"
@@ -3839,7 +3840,7 @@ static int _php_mbstr_parse_mail_headers(Array &ht, const char *str,
           if (!fld_name.empty() && !fld_val.empty()) {
             /* FIXME: some locale free implementation is
              * really required here,,, */
-            ht.set(StringUtil::ToUpper(fld_name), fld_val);
+            ht.set(f_strtoupper(fld_name), fld_val);
           }
           state = 1;
         }
@@ -3872,7 +3873,7 @@ out:
     if (!fld_name.empty() && !fld_val.empty()) {
       /* FIXME: some locale free implementation is
        * really required here,,, */
-      ht.set(StringUtil::ToUpper(fld_name), fld_val);
+      ht.set(f_strtoupper(fld_name), fld_val);
     }
   }
   return state;
diff --git a/hphp/runtime/ext/ext_pdo.cpp b/hphp/runtime/ext/ext_pdo.cpp
index 94e3dae3e..6738ec4bb 100644
--- a/hphp/runtime/ext/ext_pdo.cpp
+++ b/hphp/runtime/ext/ext_pdo.cpp
@@ -21,6 +21,7 @@
 #include "hphp/runtime/ext/ext_class.h"
 #include "hphp/runtime/ext/ext_function.h"
 #include "hphp/runtime/ext/ext_stream.h"
+#include "hphp/runtime/ext/ext_string.h"
 #include "hphp/runtime/base/class-info.h"
 #include "hphp/runtime/base/ini-setting.h"
 #include "hphp/runtime/base/string-buffer.h"
@@ -653,10 +654,10 @@ static bool pdo_stmt_describe_columns(sp_PDOStatement stmt) {
         stmt->dbh->desired_case != PDO_CASE_NATURAL) {
       switch (stmt->dbh->desired_case) {
       case PDO_CASE_UPPER:
-        name = StringUtil::ToUpper(name);
+        name = f_strtoupper(name);
         break;
       case PDO_CASE_LOWER:
-        name = StringUtil::ToLower(name);
+        name = f_strtolower(name);
         break;
       default:;
       }
diff --git a/hphp/runtime/ext/ext_process.cpp b/hphp/runtime/ext/ext_process.cpp
index 68f5db472..62dcb0ae4 100644
--- a/hphp/runtime/ext/ext_process.cpp
+++ b/hphp/runtime/ext/ext_process.cpp
@@ -18,6 +18,7 @@
 #include "hphp/runtime/ext/ext_process.h"
 #include "hphp/runtime/ext/ext_file.h"
 #include "hphp/runtime/ext/ext_function.h"
+#include "hphp/runtime/ext/ext_string.h"
 #include "hphp/runtime/base/string-buffer.h"
 #include "hphp/runtime/base/zend-string.h"
 #include "hphp/runtime/base/thread-init-fini.h"
@@ -466,8 +467,7 @@ String f_exec(CStrRef command, VRefParam output /* = null */,
     return String();
   }
 
-  return StringUtil::Trim(lines[count - 1].toString(),
-                          StringUtil::TrimType::Right);
+  return f_rtrim(lines[count - 1].toString());
 }
 
 void f_passthru(CStrRef command, VRefParam return_var /* = null */) {
@@ -514,8 +514,7 @@ String f_system(CStrRef command, VRefParam return_var /* = null */) {
     return String();
   }
 
-  return StringUtil::Trim(lines[count - 1].toString(),
-                          StringUtil::TrimType::Right);
+  return f_rtrim(lines[count - 1].toString());
 }
 
 ///////////////////////////////////////////////////////////////////////////////
diff --git a/hphp/runtime/ext/ext_reflection.cpp b/hphp/runtime/ext/ext_reflection.cpp
index fbbbcc37a..cab92a405 100644
--- a/hphp/runtime/ext/ext_reflection.cpp
+++ b/hphp/runtime/ext/ext_reflection.cpp
@@ -18,6 +18,7 @@
 #include "hphp/runtime/ext/ext_reflection.h"
 #include "hphp/runtime/ext/ext_closure.h"
 #include "hphp/runtime/ext/ext_misc.h"
+#include "hphp/runtime/ext/ext_string.h"
 #include "hphp/runtime/base/externals.h"
 #include "hphp/runtime/base/class-info.h"
 #include "hphp/runtime/base/runtime-option.h"
@@ -692,7 +693,7 @@ static Array get_class_info(const ClassInfo *cls) {
       ClassInfo::MethodInfo *m = *iter;
       Array info = Array::Create();
       set_method_info(info, m, cls);
-      arr.set(StringUtil::ToLower(m->name), info);
+      arr.set(f_strtolower(m->name), info);
     }
     ret.set(s_methods, VarNR(arr));
   }
@@ -829,7 +830,7 @@ Array f_hphp_get_class_info(CVarRef name) {
       if (m->isGenerated()) continue;
       Array info = Array::Create();
       set_method_info(info, m);
-      arr.set(StringUtil::ToLower(m->nameRef()), VarNR(info));
+      arr.set(f_strtolower(m->nameRef()), VarNR(info));
     }
 
     Func* const* clsMethods = cls->methods();
@@ -840,7 +841,7 @@ Array f_hphp_get_class_info(CVarRef name) {
       if (m->isGenerated()) continue;
       Array info = Array::Create();
       set_method_info(info, m);
-      arr.set(StringUtil::ToLower(m->nameRef()), VarNR(info));
+      arr.set(f_strtolower(m->nameRef()), VarNR(info));
     }
     ret.set(s_methods, VarNR(arr));
   }
diff --git a/hphp/runtime/ext/ext_soap.cpp b/hphp/runtime/ext/ext_soap.cpp
index 3170c0b9d..33c1a6f48 100644
--- a/hphp/runtime/ext/ext_soap.cpp
+++ b/hphp/runtime/ext/ext_soap.cpp
@@ -29,6 +29,7 @@
 #include "hphp/runtime/ext/ext_class.h"
 #include "hphp/runtime/ext/ext_output.h"
 #include "hphp/runtime/ext/ext_stream.h"
+#include "hphp/runtime/ext/ext_string.h"
 
 #include "hphp/system/systemlib.h"
 
@@ -728,7 +729,7 @@ static sdlFunctionPtr get_doc_function(sdl *sdl, xmlNodePtr params) {
 
 static sdlFunctionPtr get_function(sdl *sdl, const char *function_name) {
   if (sdl) {
-    String lowered = StringUtil::ToLower(function_name);
+    String lowered = f_strtolower(function_name);
     sdlFunctionMap::iterator iter = sdl->functions.find(lowered.data());
     if (iter == sdl->functions.end()) {
       iter = sdl->requests.find(lowered.data());
@@ -2012,7 +2013,7 @@ void c_SoapServer::t_addfunction(CVarRef func) {
                         function_name.data());
         return;
       }
-      m_soap_functions.ft.set(StringUtil::ToLower(function_name), 1);
+      m_soap_functions.ft.set(f_strtolower(function_name), 1);
       m_soap_functions.ftOriginal.set(function_name, 1);
     }
   }
@@ -2052,7 +2053,7 @@ static bool valid_function(c_SoapServer *server, Object &soap_obj,
   } else if (server->m_soap_functions.functions_all) {
     return f_function_exists(fn_name);
   } else if (!server->m_soap_functions.ft.empty()) {
-    return server->m_soap_functions.ft.exists(StringUtil::ToLower(fn_name));
+    return server->m_soap_functions.ft.exists(f_strtolower(fn_name));
   }
   HPHP::Func* f = cls->lookupMethod(fn_name.get());
   return (f && f->isPublic());
diff --git a/hphp/runtime/ext/ext_spl.cpp b/hphp/runtime/ext/ext_spl.cpp
index 95ebf14a6..04adc1486 100644
--- a/hphp/runtime/ext/ext_spl.cpp
+++ b/hphp/runtime/ext/ext_spl.cpp
@@ -18,6 +18,7 @@
 #include "hphp/runtime/ext/ext_spl.h"
 #include "hphp/runtime/ext/ext_math.h"
 #include "hphp/runtime/ext/ext_class.h"
+#include "hphp/runtime/ext/ext_string.h"
 
 #include "hphp/system/systemlib.h"
 
@@ -341,7 +342,7 @@ void f_spl_autoload(CStrRef class_name,
   Array ext = file_extensions.isNull()
               ? s_extension_list->extensions
               : StringUtil::Explode(file_extensions, ",").toArray();
-  String lClass = StringUtil::ToLower(class_name);
+  String lClass = f_strtolower(class_name);
   bool found = false;
   for (ArrayIter iter(ext); iter; ++iter) {
     String fileName = lClass + iter.second().toString();
diff --git a/hphp/runtime/ext/ext_string.cpp b/hphp/runtime/ext/ext_string.cpp
index a9c09fc0e..53ec3147a 100644
--- a/hphp/runtime/ext/ext_string.cpp
+++ b/hphp/runtime/ext/ext_string.cpp
@@ -33,71 +33,402 @@ namespace HPHP {
 static Mutex s_mutex;
 ///////////////////////////////////////////////////////////////////////////////
 
+template <class Op> inline ALWAYS_INLINE
+String stringForEachBuffered(uint32_t bufLen, CStrRef str, Op action) {
+  StringBuffer sb(bufLen);
+  StringSlice sl  = str.slice();
+  const char* src = sl.begin();
+  const char* end = sl.end();
+
+  for (; src < end; ++src) {
+    action(sb, src, end);
+  }
+
+  return sb.detach();
+}
+
+template <bool mutate, class Op> inline ALWAYS_INLINE
+String stringForEach(uint32_t len, CStrRef str, Op action) {
+  String ret = mutate ? str : String(len, ReserveString);
+
+  StringSlice srcSlice = str.slice();
+  MutableSlice dstSlice = ret.mutableSlice();
+
+  const char* src = srcSlice.begin();
+  const char* end = srcSlice.end();
+
+  char* dst = dstSlice.begin();
+
+  for (; src != end; ++src, ++dst) {
+    *dst = action(*src);
+  }
+
+  if (!mutate) ret->setSize(len);
+  return ret;
+}
+
+template <class Op> inline ALWAYS_INLINE
+String stringForEachFast(CStrRef str, Op action) {
+  if (str.empty()) {
+    return str;
+  }
+
+  if (str->getCount() == 1) {
+    return stringForEach<true>(str.size(), str, action);
+  }
+
+  return stringForEach<false>(str.size(), str, action);
+}
+
 String f_addcslashes(CStrRef str, CStrRef charlist) {
-  return StringUtil::CEncode(str, charlist);
+  if (str.empty() || (!charlist.isNull() && charlist->empty())) {
+    return str;
+  }
+
+  int masklen = charlist.isNull() ? 10 : charlist.size();
+  const char* list = charlist.isNull() ? "\\\x00\x01..\x1f\x7f..\xff"
+                                       : charlist.c_str();
+
+  char flags[256];
+  string_charmask(list, masklen, flags);
+
+  return stringForEachBuffered(str.size(), str,
+    [&] (StringBuffer& ret, const char* src, const char* end) {
+      int c = (unsigned char)*src;
+
+      if (flags[c]) {
+        ret.append('\\');
+        if ((c < 32) || (c > 126)) {
+          switch (c) {
+            case '\n': ret.append('n'); break;
+            case '\t': ret.append('t'); break;
+            case '\r': ret.append('r'); break;
+            case '\a': ret.append('a'); break;
+            case '\v': ret.append('v'); break;
+            case '\b': ret.append('b'); break;
+            case '\f': ret.append('f'); break;
+            default: ret.append((char)('0' + (c / 64))); c %= 64;
+                     ret.append((char)('0' + (c /  8))); c %=  8;
+                     ret.append((char)('0' + c));
+          }
+          return;
+        }
+      }
+      ret.append((char)c);
+    });
 }
+
 String f_stripcslashes(CStrRef str) {
-  return StringUtil::CDecode(str);
+  if (str.empty()) {
+    return str;
+  }
+
+  return stringForEachBuffered(str.size(), str,
+    [&] (StringBuffer& ret, const char*& src, const char* end) {
+      char c;
+      const char* p;
+
+      if (*src != '\\' || src + 1 == end) {
+        ret.append(*src);
+        return;
+      }
+
+      switch (*++src) {
+        case 'n': ret.append('\n'); break;
+        case 'r': ret.append('\r'); break;
+        case 'a': ret.append('\a'); break;
+        case 't': ret.append('\t'); break;
+        case 'v': ret.append('\v'); break;
+        case 'b': ret.append('\b'); break;
+        case 'f': ret.append('\f'); break;
+        case '\\': ret.append('\\'); break;
+        case 'x':
+          if (src + 1 == end || !isxdigit(src[1])) {
+            ret.append(*src);
+            break;
+          }
+
+          for (c = 0, ++src, p = src + 2; src < p && src < end &&
+               isxdigit(*src); ++src) {
+            c *= 16;
+            c += (*src < 'A' ? *src - '0' :
+                  *src < 'a' ? *src - 'A' + 10 :
+                               *src - 'a' + 10);
+          }
+          ret.append(c);
+          src--;
+          break;
+
+        default:
+          if (*src < '0' || '7' < *src) {
+            // The character after the slash is nothing special. Append it
+            // unchanged to the result.
+            ret.append(*src);
+            break;
+          }
+
+          // Decode a base 8 number up to 3 characters long.
+          for (c = 0, p = src + 3; src < p && src < end && '0' <= *src &&
+               *src < '8'; ++src) {
+            c *= 8;
+            c += (*src - '0');
+          }
+          ret.append(c);
+          src--;
+      }
+    });
 }
+
 String f_addslashes(CStrRef str) {
-  return StringUtil::SqlEncode(str);
+  if (str.empty()) {
+    return str;
+  }
+
+  return stringForEachBuffered(str.size(), str,
+    [&] (StringBuffer& ret, const char* src, const char* end) {
+      switch (*src) {
+        case '\0':
+          ret.append('\\');
+          ret.append('0');
+          break;
+        case '\\': case '\"': case '\'':
+          ret.append('\\');
+          /* fall through */
+        default:
+          ret.append(*src);
+      }
+    });
 }
+
 String f_stripslashes(CStrRef str) {
-  return StringUtil::SqlDecode(str);
+  if (str.empty()) {
+    return str;
+  }
+
+  return stringForEachBuffered(str.size(), str,
+    [&] (StringBuffer& ret, const char*& src, const char* end) {
+      if (*src == '\\' && *++src == '0') {
+        ret.append('\0');
+        return;
+      }
+      ret.append(*src);
+    });
 }
+
 String f_bin2hex(CStrRef str) {
-  return StringUtil::HexEncode(str);
+  if (str.empty()) {
+    return str;
+  }
+
+  return stringForEachBuffered(str.size(), str,
+    [&] (StringBuffer& ret, const char* src, const char* end) {
+      static char hexconvtab[] = "0123456789abcdef";
+      ret.append(hexconvtab[(unsigned char)*src >> 4]);
+      ret.append(hexconvtab[(unsigned char)*src & 15]);
+    });
 }
+
 Variant f_hex2bin(CStrRef str) {
-  try {
-    return StringUtil::HexDecode(str);
-  } catch (...) {
+  if (str.empty()) {
+    return str;
+  }
+
+  if (str.size() % 2) {
     raise_warning("hex2bin: malformed input");
     return false;
   }
+
+  StringBuffer ret(str.size() / 2 + 1);
+
+  StringSlice sl  = str.slice();
+  const char* src = sl.begin();
+  const char* end = sl.end();
+
+  for (; src != end; ++src) {
+    int val;
+    if (isdigit(*src))                   val = 16 * (*src++ - '0');
+    else if ('a' <= *src && *src <= 'f') val = 16 * (*src++ - 'a' + 10);
+    else if ('A' <= *src && *src <= 'F') val = 16 * (*src++ - 'A' + 10);
+    else {
+      raise_warning("hex2bin: malformed input");
+      return false;
+    }
+
+    if (isdigit(*src))                   val += (*src - '0');
+    else if ('a' <= *src && *src <= 'f') val += (*src - 'a' + 10);
+    else if ('A' <= *src && *src <= 'F') val += (*src - 'A' + 10);
+    else {
+      raise_warning("hex2bin: malformed input");
+      return false;
+    }
+
+    ret.append((char)val);
+  }
+
+  return ret.detach();
 }
+
 String f_nl2br(CStrRef str) {
   return str.replace("\n", "<br />\n");
 }
+
 String f_quotemeta(CStrRef str) {
-  return StringUtil::RegExEncode(str);
+  if (str.empty()) {
+    return str;
+  }
+
+  return stringForEachBuffered(str.size(), str,
+    [&] (StringBuffer& ret, const char* src, const char* end) {
+      switch (*src) {
+        case '.': case '\\': case '+': case '*': case '?': case '[': case ']':
+        case '^': case '$': case '(': case ')':
+          ret.append('\\');
+          /* fall through */
+        default:
+          ret.append(*src);
+      }
+    });
 }
+
 String f_str_shuffle(CStrRef str) {
-  return StringUtil::Shuffle(str);
+  if (str.size() <= 1) {
+    return str;
+  }
+
+  String ret = str->getCount() == 1 ? str : String(str, CopyString);
+  char* buf  = ret->mutableData();
+  int left   = ret->size();
+
+  while (--left) {
+    int idx = rand() % left;
+    char temp = buf[left];
+    buf[left] = buf[idx];
+    buf[idx] = temp;
+  }
+
+  return ret;
 }
+
 String f_strrev(CStrRef str) {
-  return StringUtil::Reverse(str);
+  auto len = str.size();
+
+  if (str->getCount() == 1) {
+    char* sdata = str->mutableData();
+    for (int i = 0; i < len / 2; ++i) {
+      char temp = sdata[i];
+      sdata[i] = sdata[len - i - 1];
+      sdata[len - i - 1] = temp;
+    }
+    return str;
+  }
+
+  String ret(len, ReserveString);
+
+  const char* data = str.data();
+  char* dest = ret->mutableData();
+
+  for (int i = 0; i < len; ++i) {
+    dest[i] = data[len - i - 1];
+  }
+
+  ret->setSize(len);
+  return ret;
 }
+
 String f_strtolower(CStrRef str) {
-  return StringUtil::ToLower(str);
+  return stringForEachFast(str, tolower);
 }
+
 String f_strtoupper(CStrRef str) {
-  return StringUtil::ToUpper(str, StringUtil::ToUpperType::All);
+  return stringForEachFast(str, toupper);
 }
+
+template <class OpTo, class OpIs> inline ALWAYS_INLINE
+String stringToCaseFirst(CStrRef str, OpTo tocase, OpIs iscase) {
+  if (str.empty() || iscase(str[0])) {
+    return str;
+  }
+
+  if (str->getCount() == 1) {
+    char* sdata = str->mutableData();
+    sdata[0] = tocase(sdata[0]);
+    return str;
+  }
+
+  String ret(str, CopyString);
+  char* first = ret->mutableData();
+
+  *first = tocase(*first);
+  return ret;
+}
+
 String f_ucfirst(CStrRef str) {
-  return StringUtil::ToUpper(str, StringUtil::ToUpperType::First);
+  return stringToCaseFirst(str, toupper, isupper);
 }
+
 String f_lcfirst(CStrRef str) {
-  return StringUtil::ToLower(str, StringUtil::ToLowerType::First);
+  return stringToCaseFirst(str, tolower, islower);
 }
+
 String f_ucwords(CStrRef str) {
-  return StringUtil::ToUpper(str, StringUtil::ToUpperType::Words);
+  char last = ' ';
+  return stringForEachFast(str, [&] (char c) {
+    char ret = isspace(last) ? toupper(c) : c;
+    last = c;
+    return ret;
+  });
 }
+
 String f_strip_tags(CStrRef str, CStrRef allowable_tags /* = "" */) {
   return StringUtil::StripHTMLTags(str, allowable_tags);
 }
+
+template <bool left, bool right> inline ALWAYS_INLINE
+String stringTrim(CStrRef str, CStrRef charlist) {
+  char flags[256];
+  string_charmask(charlist.c_str(), charlist.size(), flags);
+
+  auto len = str.size();
+  int start = 0, end = len - 1;
+
+  if (left) {
+    for (; start < len && flags[(unsigned char)str[start]]; ++start)
+      /* do nothing */;
+  }
+
+  if (right) {
+    for (; end >= start && flags[(unsigned char)str[end]]; --end) {}
+  }
+
+  if (str->getCount() == 1) {
+    int slen = end - start + 1;
+    if (start) {
+      char* sdata = str->mutableData();
+      for (int idx = 0; start < len;) sdata[idx++] = sdata[start++];
+    }
+    str->setSize(slen);
+    return str;
+  }
+
+  return str.substr(start, end - start + 1);
+}
+
 String f_trim(CStrRef str, CStrRef charlist /* = k_HPHP_TRIM_CHARLIST */) {
-  return StringUtil::Trim(str, StringUtil::TrimType::Both, charlist);
+  return stringTrim<true,true>(str, charlist);
 }
+
 String f_ltrim(CStrRef str, CStrRef charlist /* = k_HPHP_TRIM_CHARLIST */) {
-  return StringUtil::Trim(str, StringUtil::TrimType::Left, charlist);
+  return stringTrim<true,false>(str, charlist);
 }
+
 String f_rtrim(CStrRef str, CStrRef charlist /* = k_HPHP_TRIM_CHARLIST */) {
-  return StringUtil::Trim(str, StringUtil::TrimType::Right, charlist);
+  return stringTrim<false,true>(str, charlist);
 }
+
 String f_chop(CStrRef str, CStrRef charlist /* = k_HPHP_TRIM_CHARLIST */) {
-  return StringUtil::Trim(str, StringUtil::TrimType::Right, charlist);
+  return stringTrim<false,true>(str, charlist);
 }
+
 Variant f_explode(CStrRef delimiter, CStrRef str, int limit /* = 0x7FFFFFFF */) {
   return StringUtil::Explode(str, delimiter, limit);
 }
@@ -121,9 +452,11 @@ String f_implode(CVarRef arg1, CVarRef arg2 /* = null_variant */) {
 String f_join(CVarRef glue, CVarRef pieces /* = null_variant */) {
   return f_implode(glue, pieces);
 }
+
 Variant f_str_split(CStrRef str, int split_length /* = 1 */) {
   return StringUtil::Split(str, split_length);
 }
+
 Variant f_chunk_split(CStrRef body, int chunklen /* = 76 */,
                       CStrRef end /* = "\r\n" */) {
   return StringUtil::ChunkSplit(body, chunklen, end);
@@ -327,19 +660,140 @@ Variant f_substr(CStrRef str, int start, int length /* = 0x7FFFFFFF */) {
   if (ret.isNull()) return false;
   return ret;
 }
+
 String f_str_pad(CStrRef input, int pad_length, CStrRef pad_string /* = " " */,
                         int pad_type /* = k_STR_PAD_RIGHT */) {
   return StringUtil::Pad(input, pad_length, pad_string,
                          (StringUtil::PadType)pad_type);
 }
+
 String f_str_repeat(CStrRef input, int multiplier) {
-  return StringUtil::Repeat(input, multiplier);
+  if (input.empty()) {
+    return input;
+  }
+
+  if (multiplier < 0) {
+    raise_warning("Second argument has to be greater than or equal to 0");
+    return String();
+  }
+
+  if (multiplier == 0) {
+    return String("", CopyString);
+  }
+
+  if (input.size() == 1) {
+    String ret(input.size() * multiplier, ReserveString);
+
+    memset(ret->mutableData(), *input->data(), multiplier);
+    ret->setSize(multiplier);
+    return ret;
+  }
+
+  StringBuffer ret(input.size() * multiplier);
+
+  while (multiplier--) {
+    ret.append(input);
+  }
+
+  return ret.detach();
 }
+
 Variant f_wordwrap(CStrRef str, int width /* = 75 */, CStrRef wordbreak /* = "\n" */,
                    bool cut /* = false */) {
-  String ret = StringUtil::WordWrap(str, width, wordbreak, cut);
-  if (ret.isNull()) return false;
-  return ret;
+
+  if (str.empty()) {
+    return str;
+  }
+
+  if (UNLIKELY(wordbreak.empty())) {
+    throw_invalid_argument("wordbreak: (empty)");
+    return false;
+  }
+
+  if (UNLIKELY(width == 0 && cut)) {
+    throw_invalid_argument("width: can't force cut when width = 0");
+    return false;
+  }
+
+  uint32_t pos = 0;
+  auto len = str.size();
+  auto brkLen = wordbreak.size();
+  auto bufLen = !cut && brkLen == 1 ? str.size()
+          : str.size() + brkLen * str.size() / (width ?: 1);
+
+  StringBuffer ret(bufLen);
+
+  const char* brk = wordbreak.data();
+  const char* src = str.data();
+
+next_line:
+  while (pos < len) {
+    int lineWidth, spaceWidth = -1;
+
+    for (lineWidth = 0; pos + lineWidth < len &&
+         lineWidth < width; ++lineWidth) {
+      if (lineWidth >= brkLen && !bcmp(&src[pos + lineWidth - brkLen],
+                                       brk, brkLen)) {
+        ret.append(&src[pos], lineWidth);
+        pos += lineWidth;
+        goto next_line;
+      }
+
+      if (src[pos + lineWidth] == ' ') spaceWidth = lineWidth;
+    }
+
+    if (pos + lineWidth == len) {
+      ret.append(&src[pos], lineWidth);
+      break;
+    }
+
+    if (src[pos + lineWidth] == ' ') {
+      ret.append(&src[pos], lineWidth);
+      ret.append(wordbreak);
+      pos += lineWidth + 1;
+      continue;
+    }
+
+    if (spaceWidth != -1) {
+      ret.append(&src[pos], spaceWidth);
+      ret.append(wordbreak);
+      pos += spaceWidth + 1;
+      continue;
+    }
+
+    if (cut) {
+      ret.append(&src[pos], lineWidth);
+      ret.append(wordbreak);
+      pos += lineWidth;
+
+      if (!lineWidth) { // zend is weird
+        ret.append(src[pos++]);
+      }
+      continue;
+    }
+
+    for (; pos + lineWidth < len && src[pos + lineWidth] != ' ';
+         ++lineWidth) {
+      if (lineWidth >= brkLen && !bcmp(&src[pos + lineWidth - brkLen],
+                                       brk, brkLen)) {
+        ret.append(&src[pos], lineWidth);
+        pos += lineWidth;
+        lineWidth = -1;
+        goto next_line;
+      }
+    }
+
+    if (pos + lineWidth == len) {
+      ret.append(&src[pos], lineWidth);
+      break;
+    }
+
+    ret.append(&src[pos], lineWidth);
+    ret.append(wordbreak);
+    pos += lineWidth + 1;
+  }
+
+  return ret.detach();
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -351,6 +805,7 @@ Variant f_printf(int _argc, CStrRef format, CArrRef _argv /* = null_array */) {
   echo(output); free(output);
   return len;
 }
+
 Variant f_vprintf(CStrRef format, CArrRef args) {
   int len = 0; char *output = string_printf(format.data(), format.size(),
                                             args, &len);
@@ -358,12 +813,14 @@ Variant f_vprintf(CStrRef format, CArrRef args) {
   echo(output); free(output);
   return len;
 }
+
 Variant f_sprintf(int _argc, CStrRef format, CArrRef _argv /* = null_array */) {
   int len = 0;
   char *output = string_printf(format.data(), format.size(), _argv, &len);
   if (output == NULL) return false;
   return String(output, len, AttachString);
 }
+
 Variant f_vsprintf(CStrRef format, CArrRef args) {
   int len = 0;
   char *output = string_printf(format.data(), format.size(), args, &len);
@@ -433,6 +890,7 @@ String f_number_format(double number, int decimals /* = 0 */,
 int64_t f_strcmp(CStrRef str1, CStrRef str2) {
   return string_strcmp(str1.data(), str1.size(), str2.data(), str2.size());
 }
+
 Variant f_strncmp(CStrRef str1, CStrRef str2, int len) {
   if (len < 0) {
     raise_warning("Length must be greater than or equal to 0");
@@ -441,6 +899,7 @@ Variant f_strncmp(CStrRef str1, CStrRef str2, int len) {
   return string_strncmp(str1.data(), str1.size(), str2.data(), str2.size(),
                         len);
 }
+
 int64_t f_strnatcmp(CStrRef str1, CStrRef str2) {
   return string_natural_cmp(str1.data(), str1.size(), str2.data(), str2.size(),
                             false);
@@ -874,11 +1333,13 @@ String f_htmlentities(CStrRef str, int quote_style /* = k_ENT_COMPAT */,
   return StringUtil::HtmlEncode(str, (StringUtil::QuoteStyle)quote_style,
                                 scharset, true);
 }
+
 String f_htmlspecialchars_decode(CStrRef str,
                                  int quote_style /* = k_ENT_COMPAT */) {
   return StringUtil::HtmlDecode(str, (StringUtil::QuoteStyle)quote_style,
                                 "UTF-8", false);
 }
+
 String f_htmlspecialchars(CStrRef str, int quote_style /* = k_ENT_COMPAT */,
                           CStrRef charset /* = "ISO-8859-1" */,
                           bool double_encode /* = true */) {
@@ -888,18 +1349,22 @@ String f_htmlspecialchars(CStrRef str, int quote_style /* = k_ENT_COMPAT */,
   return StringUtil::HtmlEncode(str, (StringUtil::QuoteStyle)quote_style,
                                 scharset, false);
 }
+
 String f_fb_htmlspecialchars(CStrRef str, int quote_style /* = k_ENT_COMPAT */,
                              CStrRef charset /* = "ISO-8859-1" */,
                              CArrRef extra /* = Array() */) {
   return StringUtil::HtmlEncodeExtra(str, (StringUtil::QuoteStyle)quote_style,
                                      charset.data(), false, extra);
 }
+
 String f_quoted_printable_encode(CStrRef str) {
   return StringUtil::QuotedPrintableEncode(str);
 }
+
 String f_quoted_printable_decode(CStrRef str) {
   return StringUtil::QuotedPrintableDecode(str);
 }
+
 Variant f_convert_uudecode(CStrRef data) {
   String ret = StringUtil::UUDecode(data);
   if (ret.isNull()) {
@@ -907,22 +1372,28 @@ Variant f_convert_uudecode(CStrRef data) {
   }
   return ret;
 }
+
 Variant f_convert_uuencode(CStrRef data) {
   if (data.empty()) return false;
   return StringUtil::UUEncode(data);
 }
+
 String f_str_rot13(CStrRef str) {
   return StringUtil::ROT13(str);
 }
+
 int64_t f_crc32(CStrRef str) {
   return (uint32_t)StringUtil::CRC32(str);
 }
+
 String f_crypt(CStrRef str, CStrRef salt /* = "" */) {
   return StringUtil::Crypt(str, salt.c_str());
 }
+
 String f_md5(CStrRef str, bool raw_output /* = false */) {
   return StringUtil::MD5(str, raw_output);
 }
+
 String f_sha1(CStrRef str, bool raw_output /* = false */) {
   return StringUtil::SHA1(str, raw_output);
 }
diff --git a/hphp/runtime/ext/soap/encoding.cpp b/hphp/runtime/ext/soap/encoding.cpp
index 8ada9f544..95de4aa9b 100644
--- a/hphp/runtime/ext/soap/encoding.cpp
+++ b/hphp/runtime/ext/soap/encoding.cpp
@@ -18,6 +18,7 @@
 #include "hphp/runtime/ext/soap/encoding.h"
 #include "hphp/runtime/ext/soap/soap.h"
 #include "hphp/runtime/ext/ext_soap.h"
+#include "hphp/runtime/ext/ext_string.h"
 #include "hphp/runtime/base/string-buffer.h"
 
 namespace HPHP {
@@ -874,7 +875,7 @@ static Variant to_zval_hexbin(encodeTypePtr type, xmlNodePtr data) {
       throw SoapException("Encoding: Violation of encoding rules");
     }
     String str =
-      StringUtil::HexDecode(String((const char*)data->children->content));
+      f_hex2bin(String((const char*)data->children->content));
     if (str.isNull()) {
       throw SoapException("Encoding: Violation of encoding rules");
     }
@@ -978,7 +979,7 @@ static xmlNodePtr to_xml_hexbin(encodeTypePtr type, CVarRef data, int style,
   xmlAddChild(parent, ret);
   FIND_ZVAL_NULL(data, ret, style);
 
-  String str = StringUtil::HexEncode(data.toString());
+  String str = f_bin2hex(data.toString());
   xmlAddChild(ret, xmlNewTextLen(BAD_CAST(str.data()), str.size()));
 
   if (style == SOAP_ENCODED) {
diff --git a/hphp/runtime/server/http-protocol.cpp b/hphp/runtime/server/http-protocol.cpp
index 82bb462fe..77bae054f 100644
--- a/hphp/runtime/server/http-protocol.cpp
+++ b/hphp/runtime/server/http-protocol.cpp
@@ -29,6 +29,7 @@
 #include "hphp/runtime/server/replay-transport.h"
 #include "hphp/runtime/server/virtual-host.h"
 #include "hphp/runtime/base/http-client.h"
+#include "hphp/runtime/ext/ext_string.h"
 
 #define DEFAULT_POST_CONTENT_TYPE "application/x-www-form-urlencoded"
 
@@ -267,7 +268,7 @@ void HttpProtocol::PrepareSystemVariables(Transport *transport,
     // they are security-critical.
     if (RuntimeOption::LogHeaderMangle != 0) {
       String key = "HTTP_";
-      key += StringUtil::ToUpper(iter->first).replace("-","_");
+      key += f_strtoupper(iter->first).replace("-","_");
       if (server.asArrRef().exists(key)) {
         if (!(++bad_request_count % RuntimeOption::LogHeaderMangle)) {
           Logger::Warning(
@@ -283,7 +284,7 @@ void HttpProtocol::PrepareSystemVariables(Transport *transport,
 
     for (unsigned int i = 0; i < values.size(); i++) {
       String key = "HTTP_";
-      key += StringUtil::ToUpper(iter->first).replace("-", "_");
+      key += f_strtoupper(iter->first).replace("-", "_");
       server.set(key, String(values[i]));
     }
   }
diff --git a/hphp/runtime/server/libevent-server-with-takeover.cpp b/hphp/runtime/server/libevent-server-with-takeover.cpp
index 465167f53..99d336c15 100644
--- a/hphp/runtime/server/libevent-server-with-takeover.cpp
+++ b/hphp/runtime/server/libevent-server-with-takeover.cpp
@@ -17,6 +17,7 @@
 #include "hphp/runtime/server/libevent-server-with-takeover.h"
 #include "hphp/util/logger.h"
 #include "hphp/runtime/base/string-util.h"
+#include "hphp/runtime/ext/ext_string.h"
 #include "folly/String.h"
 #include <afdt.h>
 
@@ -243,7 +244,7 @@ int LibEventServerWithTakeover::getAcceptSocket() {
     Logger::Error(
         "AFDT did not receive a file descriptor: "
         "response = '%s'",
-        StringUtil::CEncode(resp, null_string).data());
+        f_addcslashes(resp, null_string).data());
     errno = EADDRINUSE;
     return -1;
   }
@@ -309,7 +310,7 @@ void LibEventServerWithTakeover::start() {
       Logger::Error(
           "Old server could not shut down: "
           "response = '%s'",
-          StringUtil::CEncode(resp, null_string).data());
+          f_addcslashes(resp, null_string).data());
     } else {
       Logger::Info("takeover: old satellites have shut down");
     }
diff --git a/hphp/test/ext/test_cpp_base.cpp b/hphp/test/ext/test_cpp_base.cpp
index 581b40c3b..79b73a084 100644
--- a/hphp/test/ext/test_cpp_base.cpp
+++ b/hphp/test/ext/test_cpp_base.cpp
@@ -28,6 +28,7 @@
 #include "hphp/runtime/server/ip-block-map.h"
 #include "hphp/test/ext/test_mysql_info.h"
 #include "hphp/system/systemlib.h"
+#include "hphp/runtime/ext/ext_string.h"
 
 ///////////////////////////////////////////////////////////////////////////////
 
@@ -170,7 +171,7 @@ bool TestCppBase::TestString() {
 
   // manipulations
   {
-    String s = StringUtil::ToLower("Test");
+    String s = f_strtolower("Test");
     VS(s.c_str(), "test");
   }
 
diff --git a/hphp/test/quick/string-util.php b/hphp/test/quick/string-util.php
new file mode 100644
index 000000000..5db9f2d5e
--- /dev/null
+++ b/hphp/test/quick/string-util.php
@@ -0,0 +1,27 @@
+<?php
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+function strtobin($str) {
+  $ret = '';
+  $sep = '';
+  for ($i = 0; $i < strlen($str); ++$i) {
+    $char = $str[$i];
+    $ret .= $sep . $char . ':' . ord($char);
+    $sep = ', ';
+  }
+  return $ret;
+}
+
+function do_string($str) {
+  var_dump(strtobin($str),
+           strtobin(stripcslashes($str)));
+}
+
+function main() {
+  do_string("12345\\:2\\");
+  do_string("12345\\:2\\4");
+  do_string("12345\\:a");
+  do_string("12345\\123");
+  do_string("12345\\12345");
+}
+main();
diff --git a/hphp/test/quick/string-util.php.expect b/hphp/test/quick/string-util.php.expect
new file mode 100644
index 000000000..c984e777c
--- /dev/null
+++ b/hphp/test/quick/string-util.php.expect
@@ -0,0 +1,10 @@
+string(52) "1:49, 2:50, 3:51, 4:52, 5:53, \:92, ::58, 2:50, \:92"
+string(46) "1:49, 2:50, 3:51, 4:52, 5:53, ::58, 2:50, \:92"
+string(58) "1:49, 2:50, 3:51, 4:52, 5:53, \:92, ::58, 2:50, \:92, 4:52"
+string(45) "1:49, 2:50, 3:51, 4:52, 5:53, ::58, 2:50, :4"
+string(46) "1:49, 2:50, 3:51, 4:52, 5:53, \:92, ::58, a:97"
+string(40) "1:49, 2:50, 3:51, 4:52, 5:53, ::58, a:97"
+string(52) "1:49, 2:50, 3:51, 4:52, 5:53, \:92, 1:49, 2:50, 3:51"
+string(34) "1:49, 2:50, 3:51, 4:52, 5:53, S:83"
+string(64) "1:49, 2:50, 3:51, 4:52, 5:53, \:92, 1:49, 2:50, 3:51, 4:52, 5:53"
+string(46) "1:49, 2:50, 3:51, 4:52, 5:53, S:83, 4:52, 5:53"