| // Copyright 2013 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. |
| |
| // ICU-based character set converter. |
| |
| #include <stdint.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "base/check.h" |
| #include "third_party/icu/source/common/unicode/ucnv.h" |
| #include "third_party/icu/source/common/unicode/ucnv_cb.h" |
| #include "third_party/icu/source/common/unicode/utypes.h" |
| #include "url/url_canon_icu.h" |
| #include "url/url_canon_internal.h" // for _itoa_s |
| |
| namespace url { |
| |
| namespace { |
| |
| // Called when converting a character that can not be represented, this will |
| // append an escaped version of the numerical character reference for that code |
| // point. It is of the form "Ӓ" and we will escape the non-digits to |
| // "%26%231234%3B". Why? This is what Netscape did back in the olden days. |
| void appendURLEscapedChar(const void* context, |
| UConverterFromUnicodeArgs* from_args, |
| const UChar* code_units, |
| int32_t length, |
| UChar32 code_point, |
| UConverterCallbackReason reason, |
| UErrorCode* err) { |
| if (reason == UCNV_UNASSIGNED) { |
| *err = U_ZERO_ERROR; |
| |
| const static int prefix_len = 6; |
| const static char prefix[prefix_len + 1] = "%26%23"; // "&#" percent-escaped |
| ucnv_cbFromUWriteBytes(from_args, prefix, prefix_len, 0, err); |
| |
| DCHECK(code_point < 0x110000); |
| char number[8]; // Max Unicode code point is 7 digits. |
| _itoa_s(code_point, number, 10); |
| int number_len = static_cast<int>(strlen(number)); |
| ucnv_cbFromUWriteBytes(from_args, number, number_len, 0, err); |
| |
| const static int postfix_len = 3; |
| const static char postfix[postfix_len + 1] = "%3B"; // ";" percent-escaped |
| ucnv_cbFromUWriteBytes(from_args, postfix, postfix_len, 0, err); |
| } |
| } |
| |
| // A class for scoping the installation of the invalid character callback. |
| class AppendHandlerInstaller { |
| public: |
| // The owner of this object must ensure that the converter is alive for the |
| // duration of this object's lifetime. |
| AppendHandlerInstaller(UConverter* converter) : converter_(converter) { |
| UErrorCode err = U_ZERO_ERROR; |
| ucnv_setFromUCallBack(converter_, appendURLEscapedChar, 0, |
| &old_callback_, &old_context_, &err); |
| } |
| |
| ~AppendHandlerInstaller() { |
| UErrorCode err = U_ZERO_ERROR; |
| ucnv_setFromUCallBack(converter_, old_callback_, old_context_, 0, 0, &err); |
| } |
| |
| private: |
| UConverter* converter_; |
| |
| UConverterFromUCallback old_callback_; |
| const void* old_context_; |
| }; |
| |
| } // namespace |
| |
| ICUCharsetConverter::ICUCharsetConverter(UConverter* converter) |
| : converter_(converter) { |
| } |
| |
| ICUCharsetConverter::~ICUCharsetConverter() = default; |
| |
| void ICUCharsetConverter::ConvertFromUTF16(const char16_t* input, |
| int input_len, |
| CanonOutput* output) { |
| // Install our error handler. It will be called for character that can not |
| // be represented in the destination character set. |
| AppendHandlerInstaller handler(converter_); |
| |
| int begin_offset = output->length(); |
| int dest_capacity = output->capacity() - begin_offset; |
| output->set_length(output->length()); |
| |
| do { |
| UErrorCode err = U_ZERO_ERROR; |
| char* dest = &output->data()[begin_offset]; |
| int required_capacity = ucnv_fromUChars(converter_, dest, dest_capacity, |
| input, input_len, &err); |
| if (err != U_BUFFER_OVERFLOW_ERROR) { |
| output->set_length(begin_offset + required_capacity); |
| return; |
| } |
| |
| // Output didn't fit, expand |
| dest_capacity = required_capacity; |
| output->Resize(begin_offset + dest_capacity); |
| } while (true); |
| } |
| |
| } // namespace url |