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cf6d68c32c
This patch adds caching for both layouts and for HarfBuzz face objects. The granularity of the cache for layouts is words, so it splits the input string at word boundaries (using a heuristic). There are is also some refactoring to reduce the amount of allocation and copying, and movement towards properly supporting contexts. The size of the caches is a fixed number of entries; thus, it is possible to consume a large amount of memory by filling the cache with lots of large strings. This should be refined towards a scheme that bounds the total memory used by the cache. Change-Id: Ie8176857e2d78656ce5479a7c04969819ef2718d
98 lines
2.7 KiB
C++
98 lines
2.7 KiB
C++
/*
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* Copyright (C) 2013 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef MINIKIN_FONT_COLLECTION_H
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#define MINIKIN_FONT_COLLECTION_H
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#include <vector>
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#include <minikin/MinikinRefCounted.h>
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#include <minikin/MinikinFont.h>
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#include <minikin/SparseBitSet.h>
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#include <minikin/FontFamily.h>
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namespace android {
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class FontCollection : public MinikinRefCounted {
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public:
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explicit FontCollection(const std::vector<FontFamily*>& typefaces);
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~FontCollection();
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const FontFamily* getFamilyForChar(uint32_t ch) const;
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class Run {
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public:
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// Do copy constructor, assignment, destructor so it can be used in vectors
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Run() : font(NULL) { }
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Run(const Run& other): font(other.font), start(other.start), end(other.end) {
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if (font) font->RefLocked();
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}
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Run& operator=(const Run& other) {
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if (other.font) other.font->RefLocked();
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if (font) font->UnrefLocked();
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font = other.font;
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start = other.start;
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end = other.end;
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return *this;
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}
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~Run() { if (font) font->UnrefLocked(); }
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MinikinFont* font;
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int start;
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int end;
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};
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void itemize(const uint16_t *string, size_t string_length, FontStyle style,
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std::vector<Run>* result) const;
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uint32_t getId() const;
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private:
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static const int kLogCharsPerPage = 8;
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static const int kPageMask = (1 << kLogCharsPerPage) - 1;
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struct FontInstance {
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SparseBitSet* mCoverage;
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FontFamily* mFamily;
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};
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struct Range {
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size_t start;
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size_t end;
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};
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// static for allocating unique id's
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static uint32_t sNextId;
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// unique id for this font collection (suitable for cache key)
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uint32_t mId;
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// Highest UTF-32 code point that can be mapped
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uint32_t mMaxChar;
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// This vector has ownership of the bitsets and typeface objects.
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std::vector<FontInstance> mInstances;
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// This vector contains pointers into mInstances
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std::vector<const FontInstance*> mInstanceVec;
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// These are offsets into mInstanceVec, one range per page
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std::vector<Range> mRanges;
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};
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} // namespace android
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#endif // MINIKIN_FONT_COLLECTION_H
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