1 /*
2  * Copyright (C) 2015 The Android Open Source Project
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 #ifndef AAPT_FORMAT_BINARY_TABLEFLATTENER_H
18 #define AAPT_FORMAT_BINARY_TABLEFLATTENER_H
19 
20 #include "android-base/macros.h"
21 
22 #include "ResourceTable.h"
23 #include "process/IResourceTableConsumer.h"
24 #include "util/BigBuffer.h"
25 
26 namespace aapt {
27 
28 // The percentage of used entries for a type for which using a sparse encoding is
29 // preferred.
30 constexpr const size_t kSparseEncodingThreshold = 60;
31 
32 struct TableFlattenerOptions {
33   // When true, types for configurations with a sparse set of entries are encoded
34   // as a sparse map of entry ID and offset to actual data.
35   // This is only available on platforms O+ and will only be respected when
36   // minSdk is O+.
37   bool use_sparse_entries = false;
38 
39   // When true, the key string pool in the final ResTable
40   // is collapsed to a single entry. All resource entries
41   // have name indices that point to this single value
42   bool collapse_key_stringpool = false;
43 
44   // Set of whitelisted resource names to avoid altering in key stringpool
45   std::set<std::string> whitelisted_resources;
46 
47   // Map from original resource paths to shortened resource paths.
48   std::map<std::string, std::string> shortened_path_map;
49 };
50 
51 class TableFlattener : public IResourceTableConsumer {
52  public:
TableFlattener(const TableFlattenerOptions & options,BigBuffer * buffer)53   explicit TableFlattener(const TableFlattenerOptions& options, BigBuffer* buffer)
54       : options_(options), buffer_(buffer) {
55   }
56 
57   bool Consume(IAaptContext* context, ResourceTable* table) override;
58 
59  private:
60   DISALLOW_COPY_AND_ASSIGN(TableFlattener);
61 
62   TableFlattenerOptions options_;
63   BigBuffer* buffer_;
64 };
65 
66 }  // namespace aapt
67 
68 #endif /* AAPT_FORMAT_BINARY_TABLEFLATTENER_H */
69