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Diffstat (limited to 'third_party/protobuf/3.4.0/src/google/protobuf/descriptor_database.h')
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diff --git a/third_party/protobuf/3.4.0/src/google/protobuf/descriptor_database.h b/third_party/protobuf/3.4.0/src/google/protobuf/descriptor_database.h new file mode 100644 index 0000000000..28f8af7a2d --- /dev/null +++ b/third_party/protobuf/3.4.0/src/google/protobuf/descriptor_database.h @@ -0,0 +1,383 @@ +// Protocol Buffers - Google's data interchange format +// Copyright 2008 Google Inc. All rights reserved. +// https://developers.google.com/protocol-buffers/ +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +// Author: kenton@google.com (Kenton Varda) +// Based on original Protocol Buffers design by +// Sanjay Ghemawat, Jeff Dean, and others. +// +// Interface for manipulating databases of descriptors. + +#ifndef GOOGLE_PROTOBUF_DESCRIPTOR_DATABASE_H__ +#define GOOGLE_PROTOBUF_DESCRIPTOR_DATABASE_H__ + +#include <map> +#include <string> +#include <utility> +#include <vector> +#include <google/protobuf/stubs/common.h> +#include <google/protobuf/descriptor.h> + +namespace google { +namespace protobuf { + +// Defined in this file. +class DescriptorDatabase; +class SimpleDescriptorDatabase; +class EncodedDescriptorDatabase; +class DescriptorPoolDatabase; +class MergedDescriptorDatabase; + +// Abstract interface for a database of descriptors. +// +// This is useful if you want to create a DescriptorPool which loads +// descriptors on-demand from some sort of large database. If the database +// is large, it may be inefficient to enumerate every .proto file inside it +// calling DescriptorPool::BuildFile() for each one. Instead, a DescriptorPool +// can be created which wraps a DescriptorDatabase and only builds particular +// descriptors when they are needed. +class LIBPROTOBUF_EXPORT DescriptorDatabase { + public: + inline DescriptorDatabase() {} + virtual ~DescriptorDatabase(); + + // Find a file by file name. Fills in in *output and returns true if found. + // Otherwise, returns false, leaving the contents of *output undefined. + virtual bool FindFileByName(const string& filename, + FileDescriptorProto* output) = 0; + + // Find the file that declares the given fully-qualified symbol name. + // If found, fills in *output and returns true, otherwise returns false + // and leaves *output undefined. + virtual bool FindFileContainingSymbol(const string& symbol_name, + FileDescriptorProto* output) = 0; + + // Find the file which defines an extension extending the given message type + // with the given field number. If found, fills in *output and returns true, + // otherwise returns false and leaves *output undefined. containing_type + // must be a fully-qualified type name. + virtual bool FindFileContainingExtension(const string& containing_type, + int field_number, + FileDescriptorProto* output) = 0; + + // Finds the tag numbers used by all known extensions of + // extendee_type, and appends them to output in an undefined + // order. This method is best-effort: it's not guaranteed that the + // database will find all extensions, and it's not guaranteed that + // FindFileContainingExtension will return true on all of the found + // numbers. Returns true if the search was successful, otherwise + // returns false and leaves output unchanged. + // + // This method has a default implementation that always returns + // false. + virtual bool FindAllExtensionNumbers(const string& /* extendee_type */, + std::vector<int>* /* output */) { + return false; + } + + + // Finds the file names and appends them to the output in an + // undefined order. This method is best-effort: it's not guaranteed that the + // database will find all files. Returns true if the database supports + // searching all file names, otherwise returns false and leaves output + // unchanged. + // + // This method has a default implementation that always returns + // false. + virtual bool FindAllFileNames(std::vector<string>* output) { + return false; + } + + private: + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(DescriptorDatabase); +}; + +// A DescriptorDatabase into which you can insert files manually. +// +// FindFileContainingSymbol() is fully-implemented. When you add a file, its +// symbols will be indexed for this purpose. Note that the implementation +// may return false positives, but only if it isn't possible for the symbol +// to be defined in any other file. In particular, if a file defines a symbol +// "Foo", then searching for "Foo.[anything]" will match that file. This way, +// the database does not need to aggressively index all children of a symbol. +// +// FindFileContainingExtension() is mostly-implemented. It works if and only +// if the original FieldDescriptorProto defining the extension has a +// fully-qualified type name in its "extendee" field (i.e. starts with a '.'). +// If the extendee is a relative name, SimpleDescriptorDatabase will not +// attempt to resolve the type, so it will not know what type the extension is +// extending. Therefore, calling FindFileContainingExtension() with the +// extension's containing type will never actually find that extension. Note +// that this is an unlikely problem, as all FileDescriptorProtos created by the +// protocol compiler (as well as ones created by calling +// FileDescriptor::CopyTo()) will always use fully-qualified names for all +// types. You only need to worry if you are constructing FileDescriptorProtos +// yourself, or are calling compiler::Parser directly. +class LIBPROTOBUF_EXPORT SimpleDescriptorDatabase : public DescriptorDatabase { + public: + SimpleDescriptorDatabase(); + ~SimpleDescriptorDatabase(); + + // Adds the FileDescriptorProto to the database, making a copy. The object + // can be deleted after Add() returns. Returns false if the file conflicted + // with a file already in the database, in which case an error will have + // been written to GOOGLE_LOG(ERROR). + bool Add(const FileDescriptorProto& file); + + // Adds the FileDescriptorProto to the database and takes ownership of it. + bool AddAndOwn(const FileDescriptorProto* file); + + // implements DescriptorDatabase ----------------------------------- + bool FindFileByName(const string& filename, + FileDescriptorProto* output); + bool FindFileContainingSymbol(const string& symbol_name, + FileDescriptorProto* output); + bool FindFileContainingExtension(const string& containing_type, + int field_number, + FileDescriptorProto* output); + bool FindAllExtensionNumbers(const string& extendee_type, + std::vector<int>* output); + + private: + // So that it can use DescriptorIndex. + friend class EncodedDescriptorDatabase; + + // An index mapping file names, symbol names, and extension numbers to + // some sort of values. + template <typename Value> + class DescriptorIndex { + public: + // Helpers to recursively add particular descriptors and all their contents + // to the index. + bool AddFile(const FileDescriptorProto& file, + Value value); + bool AddSymbol(const string& name, Value value); + bool AddNestedExtensions(const DescriptorProto& message_type, + Value value); + bool AddExtension(const FieldDescriptorProto& field, + Value value); + + Value FindFile(const string& filename); + Value FindSymbol(const string& name); + Value FindExtension(const string& containing_type, int field_number); + bool FindAllExtensionNumbers(const string& containing_type, + std::vector<int>* output); + + private: + std::map<string, Value> by_name_; + std::map<string, Value> by_symbol_; + std::map<std::pair<string, int>, Value> by_extension_; + + // Invariant: The by_symbol_ map does not contain any symbols which are + // prefixes of other symbols in the map. For example, "foo.bar" is a + // prefix of "foo.bar.baz" (but is not a prefix of "foo.barbaz"). + // + // This invariant is important because it means that given a symbol name, + // we can find a key in the map which is a prefix of the symbol in O(lg n) + // time, and we know that there is at most one such key. + // + // The prefix lookup algorithm works like so: + // 1) Find the last key in the map which is less than or equal to the + // search key. + // 2) If the found key is a prefix of the search key, then return it. + // Otherwise, there is no match. + // + // I am sure this algorithm has been described elsewhere, but since I + // wasn't able to find it quickly I will instead prove that it works + // myself. The key to the algorithm is that if a match exists, step (1) + // will find it. Proof: + // 1) Define the "search key" to be the key we are looking for, the "found + // key" to be the key found in step (1), and the "match key" to be the + // key which actually matches the serach key (i.e. the key we're trying + // to find). + // 2) The found key must be less than or equal to the search key by + // definition. + // 3) The match key must also be less than or equal to the search key + // (because it is a prefix). + // 4) The match key cannot be greater than the found key, because if it + // were, then step (1) of the algorithm would have returned the match + // key instead (since it finds the *greatest* key which is less than or + // equal to the search key). + // 5) Therefore, the found key must be between the match key and the search + // key, inclusive. + // 6) Since the search key must be a sub-symbol of the match key, if it is + // not equal to the match key, then search_key[match_key.size()] must + // be '.'. + // 7) Since '.' sorts before any other character that is valid in a symbol + // name, then if the found key is not equal to the match key, then + // found_key[match_key.size()] must also be '.', because any other value + // would make it sort after the search key. + // 8) Therefore, if the found key is not equal to the match key, then the + // found key must be a sub-symbol of the match key. However, this would + // contradict our map invariant which says that no symbol in the map is + // a sub-symbol of any other. + // 9) Therefore, the found key must match the match key. + // + // The above proof assumes the match key exists. In the case that the + // match key does not exist, then step (1) will return some other symbol. + // That symbol cannot be a super-symbol of the search key since if it were, + // then it would be a match, and we're assuming the match key doesn't exist. + // Therefore, step 2 will correctly return no match. + + // Find the last entry in the by_symbol_ map whose key is less than or + // equal to the given name. + typename std::map<string, Value>::iterator FindLastLessOrEqual( + const string& name); + + // True if either the arguments are equal or super_symbol identifies a + // parent symbol of sub_symbol (e.g. "foo.bar" is a parent of + // "foo.bar.baz", but not a parent of "foo.barbaz"). + bool IsSubSymbol(const string& sub_symbol, const string& super_symbol); + + // Returns true if and only if all characters in the name are alphanumerics, + // underscores, or periods. + bool ValidateSymbolName(const string& name); + }; + + + DescriptorIndex<const FileDescriptorProto*> index_; + std::vector<const FileDescriptorProto*> files_to_delete_; + + // If file is non-NULL, copy it into *output and return true, otherwise + // return false. + bool MaybeCopy(const FileDescriptorProto* file, + FileDescriptorProto* output); + + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(SimpleDescriptorDatabase); +}; + +// Very similar to SimpleDescriptorDatabase, but stores all the descriptors +// as raw bytes and generally tries to use as little memory as possible. +// +// The same caveats regarding FindFileContainingExtension() apply as with +// SimpleDescriptorDatabase. +class LIBPROTOBUF_EXPORT EncodedDescriptorDatabase : public DescriptorDatabase { + public: + EncodedDescriptorDatabase(); + ~EncodedDescriptorDatabase(); + + // Adds the FileDescriptorProto to the database. The descriptor is provided + // in encoded form. The database does not make a copy of the bytes, nor + // does it take ownership; it's up to the caller to make sure the bytes + // remain valid for the life of the database. Returns false and logs an error + // if the bytes are not a valid FileDescriptorProto or if the file conflicted + // with a file already in the database. + bool Add(const void* encoded_file_descriptor, int size); + + // Like Add(), but makes a copy of the data, so that the caller does not + // need to keep it around. + bool AddCopy(const void* encoded_file_descriptor, int size); + + // Like FindFileContainingSymbol but returns only the name of the file. + bool FindNameOfFileContainingSymbol(const string& symbol_name, + string* output); + + // implements DescriptorDatabase ----------------------------------- + bool FindFileByName(const string& filename, + FileDescriptorProto* output); + bool FindFileContainingSymbol(const string& symbol_name, + FileDescriptorProto* output); + bool FindFileContainingExtension(const string& containing_type, + int field_number, + FileDescriptorProto* output); + bool FindAllExtensionNumbers(const string& extendee_type, + std::vector<int>* output); + + private: + SimpleDescriptorDatabase::DescriptorIndex<std::pair<const void*, int> > + index_; + std::vector<void*> files_to_delete_; + + // If encoded_file.first is non-NULL, parse the data into *output and return + // true, otherwise return false. + bool MaybeParse(std::pair<const void*, int> encoded_file, + FileDescriptorProto* output); + + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(EncodedDescriptorDatabase); +}; + +// A DescriptorDatabase that fetches files from a given pool. +class LIBPROTOBUF_EXPORT DescriptorPoolDatabase : public DescriptorDatabase { + public: + explicit DescriptorPoolDatabase(const DescriptorPool& pool); + ~DescriptorPoolDatabase(); + + // implements DescriptorDatabase ----------------------------------- + bool FindFileByName(const string& filename, + FileDescriptorProto* output); + bool FindFileContainingSymbol(const string& symbol_name, + FileDescriptorProto* output); + bool FindFileContainingExtension(const string& containing_type, + int field_number, + FileDescriptorProto* output); + bool FindAllExtensionNumbers(const string& extendee_type, + std::vector<int>* output); + + private: + const DescriptorPool& pool_; + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(DescriptorPoolDatabase); +}; + +// A DescriptorDatabase that wraps two or more others. It first searches the +// first database and, if that fails, tries the second, and so on. +class LIBPROTOBUF_EXPORT MergedDescriptorDatabase : public DescriptorDatabase { + public: + // Merge just two databases. The sources remain property of the caller. + MergedDescriptorDatabase(DescriptorDatabase* source1, + DescriptorDatabase* source2); + // Merge more than two databases. The sources remain property of the caller. + // The vector may be deleted after the constructor returns but the + // DescriptorDatabases need to stick around. + explicit MergedDescriptorDatabase( + const std::vector<DescriptorDatabase*>& sources); + ~MergedDescriptorDatabase(); + + // implements DescriptorDatabase ----------------------------------- + bool FindFileByName(const string& filename, + FileDescriptorProto* output); + bool FindFileContainingSymbol(const string& symbol_name, + FileDescriptorProto* output); + bool FindFileContainingExtension(const string& containing_type, + int field_number, + FileDescriptorProto* output); + // Merges the results of calling all databases. Returns true iff any + // of the databases returned true. + bool FindAllExtensionNumbers(const string& extendee_type, + std::vector<int>* output); + + + private: + std::vector<DescriptorDatabase*> sources_; + GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(MergedDescriptorDatabase); +}; + +} // namespace protobuf + +} // namespace google +#endif // GOOGLE_PROTOBUF_DESCRIPTOR_DATABASE_H__ |