zip.h revision 89b255ab712cb7c93e99799fb2216f81e8391730
1// Copyright 2015 Google Inc. All rights reserved. 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// http://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13// limitations under the License. 14// 15// zip.h -- .zip (.jar) file reading/writing routines. 16// 17// This file specifies the interface to use the ZIP implementation of ijar. 18// 19 20#ifndef INCLUDED_THIRD_PARTY_IJAR_ZIP_H 21#define INCLUDED_THIRD_PARTY_IJAR_ZIP_H 22 23#include <sys/stat.h> 24 25#include "common.h" 26 27namespace devtools_ijar { 28 29// Tells if this is a directory entry from the mode. This method 30// is safer than zipattr_to_mode(attr) & S_IFDIR because the unix 31// mode might not be set in DOS zip files. 32inline bool zipattr_is_dir(u4 attr) { return (attr & 0x10) != 0; } 33 34// Convert a Unix file mode to a ZIP file attribute 35inline u4 mode_to_zipattr(mode_t m) { 36 return (((u4) m) << 16) + ((m & S_IFDIR) != 0 ? 0x10 : 0); 37} 38 39// Convert a ZIP file attribute to a Unix file mode 40inline mode_t zipattr_to_mode(u4 attr) { 41 return ((mode_t) ((attr >> 16) & 0xffff)); 42} 43 44// 45// Class interface for building ZIP files 46// 47class ZipBuilder { 48 public: 49 virtual ~ZipBuilder() {} 50 51 // Returns the text for the last error, or null on no last error. 52 virtual const char* GetError() = 0; 53 54 // Add a new file to the ZIP, the file will have path "filename" 55 // and external attributes "attr". This function returns a pointer 56 // to a memory buffer to write the data of the file into. This buffer 57 // is owned by ZipBuilder and should not be free'd by the caller. The 58 // file length is then specified when the files is finished written 59 // using the FinishFile(size_t) function. 60 // On failure, returns NULL and GetError() will return an non-empty message. 61 virtual u1* NewFile(const char* filename, const u4 attr) = 0; 62 63 // Finish writing a file and specify its length. After calling this method 64 // one should not reuse the pointer given by NewFile. The file can be 65 // compressed using the deflate algorithm by setting `compress` to true. 66 // By default, CRC32 are not computed as java tooling doesn't care, but 67 // computing it can be activated by setting `compute_crc` to true. 68 // On failure, returns -1 and GetError() will return an non-empty message. 69 virtual int FinishFile(size_t filelength, 70 bool compress = false, 71 bool compute_crc = false) = 0; 72 73 // Write an empty file, it is equivalent to: 74 // NewFile(filename, 0); 75 // FinishFile(0); 76 // On failure, returns -1 and GetError() will return an non-empty message. 77 virtual int WriteEmptyFile(const char* filename) = 0; 78 79 // Finish writing the ZIP file. This method can be called only once 80 // (subsequent calls will do nothing) and none of 81 // NewFile/FinishFile/WriteEmptyFile should be called after calling Finish. If 82 // this method was not called when the object is destroyed, it will be called. 83 // It is here as a convenience to get information on the final generated ZIP 84 // file. 85 // On failure, returns -1 and GetError() will return an non-empty message. 86 virtual int Finish() = 0; 87 88 // Get the current size of the ZIP file. This size will not be matching the 89 // final ZIP file until Finish() has been called because Finish() is actually 90 // writing the central directory of the ZIP File. 91 virtual size_t GetSize() = 0; 92 93 // Returns the current number of files stored in the ZIP. 94 virtual int GetNumberFiles() = 0; 95 96 // Create a new ZipBuilder writing the file zip_file and the size of the 97 // output will be at most estimated_size. Use ZipBuilder::EstimateSize() or 98 // ZipExtractor::CalculateOuputLength() to have an estimated_size depending on 99 // a list of file to store. 100 // On failure, returns NULL. Refer to errno for error code. 101 static ZipBuilder* Create(const char* zip_file, u8 estimated_size); 102 103 // Estimate the maximum size of the ZIP files containing files in the "files" 104 // null-terminated array. 105 // Returns 0 on error. 106 static u8 EstimateSize(char **files); 107}; 108 109// 110// An abstract class to process data from a ZipExtractor. 111// Derive from this class if you wish to process data from a ZipExtractor. 112// 113class ZipExtractorProcessor { 114 public: 115 virtual ~ZipExtractorProcessor() {} 116 117 // Tells whether to skip or process the file "filename". "attr" is the 118 // external file attributes and can be converted to unix mode using the 119 // zipattr_to_mode() function. This method is suppoed to returns true 120 // if the file should be processed and false if it should be skipped. 121 virtual bool Accept(const char* filename, const u4 attr) = 0; 122 123 // Process a file accepted by Accept. The file "filename" has external 124 // attributes "attr" and length "size". The file content is accessible 125 // in the buffer pointed by "data". 126 virtual void Process(const char* filename, const u4 attr, 127 const u1* data, const size_t size) = 0; 128}; 129 130// 131// Class interface for reading ZIP files 132// 133class ZipExtractor { 134 public: 135 virtual ~ZipExtractor() {} 136 137 // Returns the text for the last error, or null on no last error. 138 virtual const char* GetError() = 0; 139 140 // Process the next files, returns false if the end of ZIP file has been 141 // reached. The processor provided by the Create method will be called 142 // if a file is encountered. If false is returned, check the return value 143 // of GetError() for potential errors. 144 virtual bool ProcessNext() = 0; 145 146 // Process the all files, returns -1 on error (GetError() will be populated 147 // on error). 148 virtual int ProcessAll(); 149 150 // Reset the file pointer to the beginning. 151 virtual void Reset() = 0; 152 153 // Return the size of the ZIP file. 154 virtual size_t GetSize() = 0; 155 156 // Return the size of the resulting zip file by keeping only file 157 // accepted by the processor and storing them uncompressed. This 158 // method can be used to create a ZipBuilder for storing a subset 159 // of the input files. 160 // On error, 0 is returned and GetError() returns a non-empty message. 161 virtual u8 CalculateOutputLength() = 0; 162 163 // Create a ZipExtractor that extract the zip file "filename" and process 164 // it with "processor". 165 // On error, a null pointer is returned and the value of errno should be 166 // checked. 167 static ZipExtractor* Create(const char* filename, 168 ZipExtractorProcessor *processor); 169}; 170 171} // namespace devtools_ijar 172 173#endif // INCLUDED_THIRD_PARTY_IJAR_ZIP_H 174