1 /* 2 * Copyright 2011 Google Inc. All Rights Reserved. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "sfntly/data/font_data.h" 18 19 #include <algorithm> 20 #include <functional> 21 #include <limits> 22 23 #include "sfntly/port/logging.h" 24 25 namespace sfntly { 26 27 int32_t FontData::Size() const { 28 return std::min<int32_t>(array_->Size() - bound_offset_, bound_length_); 29 } 30 31 void FontData::Bound(int32_t offset, int32_t length) { 32 // Inputs should not be negative. 33 CHECK(offset >= 0); 34 CHECK(length >= 0); 35 36 // Check to make sure |bound_offset_| will not overflow. 37 CHECK(bound_offset_ <= std::numeric_limits<int32_t>::max() - offset); 38 const int32_t new_offset = bound_offset_ + offset; 39 40 if (length == GROWABLE_SIZE) { 41 // When |length| has the special value of GROWABLE_SIZE, it means the size 42 // should not have any artificial limits, thus it is just the underlying 43 // |array_|'s size. Just make sure |new_offset| is still within bounds. 44 CHECK(new_offset <= array_->Size()); 45 } else { 46 // When |length| has any other value, |new_offset| + |length| points to the 47 // end of the array. Make sure that is within bounds, but use subtraction to 48 // avoid an integer overflow. 49 CHECK(new_offset <= array_->Size() - length); 50 } 51 52 bound_offset_ = new_offset; 53 bound_length_ = length; 54 } 55 56 int32_t FontData::Length() const { 57 return std::min<int32_t>(array_->Length() - bound_offset_, bound_length_); 58 } 59 60 FontData::FontData(ByteArray* ba) { 61 Init(ba); 62 } 63 64 FontData::FontData(FontData* data, int32_t offset, int32_t length) { 65 Init(data->array_); 66 Bound(data->bound_offset_ + offset, length); 67 } 68 69 FontData::FontData(FontData* data, int32_t offset) { 70 Init(data->array_); 71 Bound(data->bound_offset_ + offset, 72 (data->bound_length_ == GROWABLE_SIZE) 73 ? GROWABLE_SIZE : data->bound_length_ - offset); 74 } 75 76 FontData::~FontData() {} 77 78 void FontData::Init(ByteArray* ba) { 79 array_ = ba; 80 bound_offset_ = 0; 81 bound_length_ = GROWABLE_SIZE; 82 } 83 84 int32_t FontData::BoundOffset(int32_t offset) { 85 return offset + bound_offset_; 86 } 87 88 int32_t FontData::BoundLength(int32_t offset, int32_t length) { 89 return std::min<int32_t>(length, bound_length_ - offset); 90 } 91 92 } // namespace sfntly 93
