Add a new QUIC platform API for text utilities.

net/quic/platform/impl/quic_text_utils_impl.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NET_QUIC_PLATFORM_IMPL_QUIC_TEXT_UTILS_IMPL_H_
+#define NET_QUIC_PLATFORM_IMPL_QUIC_TEXT_UTILS_IMPL_H_
+
+#include <algorithm>
+
+#include "base/base64.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_piece.h"
+#include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
+
+namespace net {
+
+// google3 implementation of QuicTextUtils.
+class QuicTextUtilsImpl {
+ public:
+  // Returns true of |data| starts with |prefix|, case sensitively.
+  static bool StartsWith(base::StringPiece data, base::StringPiece prefix) {
+    return base::StartsWith(data, prefix, base::CompareCase::SENSITIVE);
+  }
+
+  // Returns true of |data| ends with |suffix|, case insensitively.
+  static bool EndsWithIgnoreCase(base::StringPiece data,
+                                 base::StringPiece suffix) {
+    return base::EndsWith(data, suffix, base::CompareCase::INSENSITIVE_ASCII);
+  }
+
+  // Returns a new std::string in which |data| has been converted to lower case.
+  static std::string ToLower(base::StringPiece data) {
+    return base::ToLowerASCII(data);
+  }
+
+  // Remove leading and trailing whitespace from |data|.
+  static void RemoveLeadingAndTrailingWhitespace(base::StringPiece* data) {
+    *data = base::TrimWhitespaceASCII(*data, base::TRIM_ALL);
+  }
+
+  // Returns true if |in| represents a valid uint64, and stores that value in
+  // |out|.
+  static bool StringToUint64(base::StringPiece in, uint64_t* out) {
+    return base::StringToUint64(in, out);
+  }
+
+  // Returns a new std::string representing |in|.
+  static std::string Uint64ToString(uint64_t in) {
+    return base::Uint64ToString(in);
+  }
+
+  // This converts |length| bytes of binary to a 2*|length|-character
+  // hexadecimal representation.
+  // Return value: 2*|length| characters of ASCII std::string.
+  static std::string HexEncode(base::StringPiece data) {
+    return base::ToLowerASCII(::base::HexEncode(data.data(), data.size()));
+  }
+
+  // Converts |data| from a hexadecimal ASCII string to a binary string
+  // that is |data.length()/2| bytes long.
+  static std::string HexDecode(base::StringPiece data) {
+    if (data.empty())
+      return "";
+    std::vector<uint8_t> v;
+    if (!base::HexStringToBytes(data.as_string(), &v))
+      return "";
+    std::string out;
+    if (!v.empty())
+      out.assign(reinterpret_cast<const char*>(&v[0]), v.size());
+    return out;
+  }
+
+  // Base64 encodes with no padding |data_len| bytes of |data| into |output|.
+  static void Base64Encode(const uint8_t* data,
+                           size_t data_len,
+                           std::string* output) {
+    base::Base64Encode(
+        std::string(reinterpret_cast<const char*>(data), data_len), output);
+    // Remove padding.
+    size_t len = output->size();
+    if (len >= 2) {
+      if ((*output)[len - 1] == '=') {
+        len--;
+        if ((*output)[len - 1] == '=') {
+          len--;
+        }
+        output->resize(len);
+      }
+    }
+  }
+
+  // Returns a std::string containing hex and ASCII representations of |binary|,
+  // side-by-side in the style of hexdump. Non-printable characters will be
+  // printed as '.' in the ASCII output.
+  // For example, given the input "Hello, QUIC!\01\02\03\04", returns:
+  // "0x0000:  4865 6c6c 6f2c 2051 5549 4321 0102 0304  Hello,.QUIC!...."
+  static std::string HexDump(base::StringPiece binary_input) {
+    int offset = 0;
+    const int kBytesPerLine = 16;  // Max bytes dumped per line
+    const char* buf = binary_input.data();
+    int bytes_remaining = binary_input.size();
+    std::string s;  // our output
+    const char* p = buf;
+    while (bytes_remaining > 0) {
+      const int line_bytes = std::min(bytes_remaining, kBytesPerLine);
+      base::StringAppendF(&s, "0x%04x:  ", offset);  // Do the line header
+      for (int i = 0; i < kBytesPerLine; ++i) {
+        if (i < line_bytes) {
+          base::StringAppendF(&s, "%02x", static_cast<unsigned char>(p[i]));
+        } else {
+          s += "  ";  // two-space filler instead of two-space hex digits
+        }
+        if (i % 2)
+          s += ' ';
+      }
+      s += ' ';
+      for (int i = 0; i < line_bytes; ++i) {  // Do the ASCII dump
+        s += (p[i] > 32 && p[i] < 127) ? p[i] : '.';
+      }
+
+      bytes_remaining -= line_bytes;
+      offset += line_bytes;
+      p += line_bytes;
+      s += '\n';
+    }
+    return s;
+  }
+
+  // Returns true if |data| contains any uppercase characters.
+  static bool ContainsUpperCase(base::StringPiece data) {
+    return std::any_of(data.begin(), data.end(), base::IsAsciiUpper<char>);
+  }
+
+  // Splits |data| into a vector of pieces delimited by |delim|.
+  static std::vector<base::StringPiece> Split(base::StringPiece data,
+                                              char delim) {
+    return base::SplitStringPiece(data, base::StringPiece(&delim, 1),
+                                  base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
+  }
+};
+
+}  // namespace net
+
+#endif  // NET_QUIC_PLATFORM_IMPL_QUIC_TEXT_UTILS_IMPL_H_