Revert 237638 "Build liblouis_nacl using gyp."

trunk/src/third_party/liblouis/nacl_wrapper/liblouis_wrapper.cc

-// Copyright 2013 Google Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License"); you may not
-// use this file except in compliance with the License. You may obtain a copy of
-// the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-// License for the specific language governing permissions and limitations under
-// the License.
-
-#include "liblouis_wrapper.h"
-
-#include <cstddef>
-
-#include "liblouis/liblouis.h"
-
-namespace {
-
-// Decodes UTF-8 into 16-bit wide characters.
-// This implementation is very permissive and may miss encoding errors.
-// It ignores charaters which are not in the Unicode Basic Multilingual Plane.
-// TODO(jbroman): Handle more than BMP if liblouis changes to accept UTF-16.
-static bool DecodeUtf8(const std::string& in, std::vector<widechar>* out) {
-  int len = in.length();
-  std::vector<widechar> result;
-  result.reserve(len);
-  int i = 0;
-  while (i < len) {
-    int ch = static_cast<unsigned char>(in[i++]);
-    widechar cp;
-    if ((ch & 0x80) == 0x00) {                      // U+0000 - U+007F
-      cp = ch;
-    } else if ((ch & 0xe0) == 0xc0 && i < len) {    // U+0080 - U+07FF
-      cp = (ch & 0x1f) << 6;
-      ch = static_cast<unsigned char>(in[i++]);
-      cp |= (ch & 0x3f);
-    } else if ((ch & 0xf0) == 0xe0 && i+1 < len) {  // U+0800 - U+FFFF
-      cp = (ch & 0x0f) << 12;
-      ch = static_cast<unsigned char>(in[i++]);
-      cp |= (ch & 0x3f) << 6;
-      ch = static_cast<unsigned char>(in[i++]);
-      cp |= (ch & 0x3f);
-    } else if ((ch & 0xf8) == 0xf0 && i+2 < len) {  // U+10000 - U+1FFFFF
-      i += 3;
-      continue;
-    } else if ((ch & 0xfc) == 0xf8 && i+3 < len) {  // U+200000 - U+3FFFFFF
-      i += 4;
-      continue;
-    } else if ((ch & 0xfe) == 0xfc && i+4 < len) {  // U+4000000 - U+7FFFFFFF
-      i += 5;
-      continue;
-    } else {
-      // Invalid first code point.
-      return false;
-    }
-    result.push_back(cp);
-  }
-  out->swap(result);
-  return true;
-}
-
-// Encodes 16-bit wide characters into UTF-8.
-// This implementation is very permissive and may miss invalid code points in
-// its input.
-// TODO(jbroman): Handle more than BMP if widechar ever becomes larger.
-static bool EncodeUtf8(const std::vector<widechar>& in, std::string* out) {
-  std::string result;
-  result.reserve(in.size() * 2);
-  for (std::vector<widechar>::const_iterator it = in.begin(); it != in.end();
-      ++it) {
-    unsigned int cp = *it;
-    if (cp <= 0x007f) {         // U+0000 - U+007F
-      result.push_back(static_cast<char>(cp));
-    } else if (cp <= 0x07ff) {  // U+0080 - U+07FF
-      result.push_back(static_cast<char>(0xc0 | ((cp >> 6) & 0x1f)));
-      result.push_back(static_cast<char>(0x80 | (cp & 0x3f)));
-    } else if (cp <= 0xffff) {  // U+0800 - U+FFFF
-      result.push_back(static_cast<char>(0xe0 | ((cp >> 12) & 0x0f)));
-      result.push_back(static_cast<char>(0x80 | ((cp >> 6) & 0x3f)));
-      result.push_back(static_cast<char>(0x80 | (cp & 0x3f)));
-    } else {
-      // This can't happen if widechar is 16 bits wide.
-      // TODO(jbroman): assert this
-    }
-  }
-  out->swap(result);
-  return true;
-}
-
-}  // namespace
-
-
-namespace liblouis_nacl {
-
-LibLouisWrapper::LibLouisWrapper() {
-  char data_path[] = "/";  // Needed because lou_setDataPath takes a char*.
-  lou_setDataPath(data_path);
-}
-
-LibLouisWrapper::~LibLouisWrapper() {
-  lou_free();
-}
-
-const char* LibLouisWrapper::tables_dir() const {
-  return "/liblouis/tables";
-}
-
-bool LibLouisWrapper::CheckTable(const std::string& table_name) {
-  return lou_getTable(table_name.c_str()) != NULL;
-}
-
-bool LibLouisWrapper::Translate(const TranslationParams& params,
-    TranslationResult* out) {
-  // Convert the character set of the input text.
-  std::vector<widechar> inbuf;
-  if (!DecodeUtf8(params.text, &inbuf)) {
-    // TODO(jbroman): log this
-    return false;
-  }
-
-  int inlen = inbuf.size();
-  int outlen = inlen * 2;  // TODO(jbroman): choose this size more accurately.
-  std::vector<widechar> outbuf(outlen);
-  std::vector<int> text_to_braille(inlen);
-  std::vector<int> braille_to_text(outlen);
-
-  // Compute the cursor position pointer to pass to liblouis.
-  int out_cursor_position;
-  int* out_cursor_position_ptr;
-  if (params.cursor_position < 0) {
-    out_cursor_position = -1;
-    out_cursor_position_ptr = NULL;
-  } else {
-    out_cursor_position = params.cursor_position;
-    out_cursor_position_ptr = &out_cursor_position;
-  }
-
-  // Invoke liblouis.
-  int result = lou_translate(params.table_name.c_str(),
-      &inbuf[0], &inlen, &outbuf[0], &outlen,
-      NULL /* typeform */, NULL /* spacing */,
-      &text_to_braille[0], &braille_to_text[0],
-      out_cursor_position_ptr, dotsIO /* mode */);
-  if (result == 0) {
-    // TODO(jbroman): log this
-    return false;
-  }
-
-  // Massage the result.
-  std::vector<unsigned char> cells;
-  cells.reserve(outlen);
-  for (int i = 0; i < outlen; i++) {
-    cells.push_back(outbuf[i]);
-  }
-  braille_to_text.resize(outlen);
-
-  // Return the translation result.
-  out->cells.swap(cells);
-  out->text_to_braille.swap(text_to_braille);
-  out->braille_to_text.swap(braille_to_text);
-  out->cursor_position = out_cursor_position;
-  return true;
-}
-
-bool LibLouisWrapper::BackTranslate(const std::string& table_name,
-    const std::vector<unsigned char>& cells, std::string* out) {
-  std::vector<widechar> inbuf;
-  inbuf.reserve(cells.size());
-  for (std::vector<unsigned char>::const_iterator it = cells.begin();
-      it != cells.end(); ++it) {
-    // Set the high-order bit to prevent liblouis from dropping empty cells.
-    inbuf.push_back(*it | 0x8000);
-  }
-  int inlen = inbuf.size();
-  int outlen = inlen * 2;  // TODO(jbroman): choose this size more accurately.
-  std::vector<widechar> outbuf(outlen);
-
-  // Invoke liblouis.
-  int result = lou_backTranslateString(table_name.c_str(),
-      &inbuf[0], &inlen, &outbuf[0], &outlen,
-      NULL /* typeform */, NULL /* spacing */, dotsIO /* mode */);
-  if (result == 0) {
-    // TODO(njbroman): log this
-    return false;
-  }
-
-  // Massage the result.
-  outbuf.resize(outlen);
-  std::string text;
-  if (!EncodeUtf8(outbuf, &text)) {
-    // TODO(jbroman): log this
-    return false;
-  }
-
-  // Return the back translation result.
-  out->swap(text);
-  return true;
-}
-
-}  // namespace liblouis_nacl