descriptor_database.h

descriptor_database.h

#include
namespace google::protobuf

Interface for manipulating databases of descriptors.

Classes in this file
DescriptorDatabase Abstract interface for a database of descriptors.
SimpleDescriptorDatabase A  DescriptorDatabase into which you can insert files manually.
EncodedDescriptorDatabase Very similar to  SimpleDescriptorDatabase, but stores all the descriptors as raw bytes and generally tries to use as little memory as possible.
DescriptorPoolDatabase A  DescriptorDatabase that fetches files from a given pool.
MergedDescriptorDatabase A  DescriptorDatabase that wraps two or more others.

class DescriptorDatabase

#include
namespace google::protobuf

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.

Known subclasses:

• SourceTreeDescriptorDatabase
• DescriptorPoolDatabase
• EncodedDescriptorDatabase
• MergedDescriptorDatabase
• SimpleDescriptorDatabase

Members
	DescriptorDatabase()
virtual	~DescriptorDatabase()
virtual bool	FindFileByName(const string & filename, FileDescriptorProto * output) = 0 Find a file by file name.  more...
virtual bool	FindFileContainingSymbol(const string & symbol_name, FileDescriptorProto * output) = 0 Find the file that declares the given fully-qualified symbol name.  more...
virtual bool	FindFileContainingExtension(const string & containing_type, int field_number, FileDescriptorProto * output) = 0 Find the file which defines an extension extending the given message type with the given field number.  more...
virtual bool	FindAllExtensionNumbers(const string & extendee_type, vector< int > * output) Finds the tag numbers used by all known extensions of extendee_type, and appends them to output in an undefined order. more...

---

virtual bool DescriptorDatabase::FindFileByName(
        const string & filename,
        FileDescriptorProto * output) = 0

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 DescriptorDatabase::FindFileContainingSymbol(
        const string & symbol_name,
        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 DescriptorDatabase::FindFileContainingExtension(
        const string & containing_type,
        int field_number,
        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 DescriptorDatabase::FindAllExtensionNumbers(
        const string & extendee_type,
        vector< int > * output)

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.

class SimpleDescriptorDatabase: public DescriptorDatabase

#include
namespace google::protobuf

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.

Members
	SimpleDescriptorDatabase()
	~SimpleDescriptorDatabase()
bool	Add(const FileDescriptorProto & file) Adds the  FileDescriptorProto to the database, making a copy.  more...
bool	AddAndOwn(const FileDescriptorProto * file) Adds the  FileDescriptorProto to the database and takes ownership of it.
implements DescriptorDatabase
virtual bool	FindFileByName(const string & filename, FileDescriptorProto * output) Find a file by file name.  more...
virtual bool	FindFileContainingSymbol(const string & symbol_name, FileDescriptorProto * output) Find the file that declares the given fully-qualified symbol name.  more...
virtual bool	FindFileContainingExtension(const string & containing_type, int field_number, FileDescriptorProto * output) Find the file which defines an extension extending the given message type with the given field number.  more...
virtual bool	FindAllExtensionNumbers(const string & extendee_type, vector< int > * output) Finds the tag numbers used by all known extensions of extendee_type, and appends them to output in an undefined order. more...

---

bool SimpleDescriptorDatabase::Add(
        const FileDescriptorProto & file)

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).

---

virtual bool SimpleDescriptorDatabase::FindFileByName(
        const string & filename,
        FileDescriptorProto * output)

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 SimpleDescriptorDatabase::FindFileContainingSymbol(
        const string & symbol_name,
        FileDescriptorProto * output)

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 SimpleDescriptorDatabase::FindFileContainingExtension(
        const string & containing_type,
        int field_number,
        FileDescriptorProto * output)

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 SimpleDescriptorDatabase::FindAllExtensionNumbers(
        const string & extendee_type,
        vector< int > * output)

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.

class EncodedDescriptorDatabase: public DescriptorDatabase

#include
namespace google::protobuf

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.

Members
	EncodedDescriptorDatabase()
	~EncodedDescriptorDatabase()
bool	Add(const void * encoded_file_descriptor, int size) Adds the  FileDescriptorProto to the database.  more...
bool	AddCopy(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	FindNameOfFileContainingSymbol(const string & symbol_name, string * output) Like FindFileContainingSymbol but returns only the name of the file.
implements DescriptorDatabase
virtual bool	FindFileByName(const string & filename, FileDescriptorProto * output) Find a file by file name.  more...
virtual bool	FindFileContainingSymbol(const string & symbol_name, FileDescriptorProto * output) Find the file that declares the given fully-qualified symbol name.  more...
virtual bool	FindFileContainingExtension(const string & containing_type, int field_number, FileDescriptorProto * output) Find the file which defines an extension extending the given message type with the given field number.  more...
virtual bool	FindAllExtensionNumbers(const string & extendee_type, vector< int > * output) Finds the tag numbers used by all known extensions of extendee_type, and appends them to output in an undefined order. more...

---

bool EncodedDescriptorDatabase::Add(
        const void * encoded_file_descriptor,
        int size)

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.

---

virtual bool EncodedDescriptorDatabase::FindFileByName(
        const string & filename,
        FileDescriptorProto * output)

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 EncodedDescriptorDatabase::FindFileContainingSymbol(
        const string & symbol_name,
        FileDescriptorProto * output)

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 EncodedDescriptorDatabase::FindFileContainingExtension(
        const string & containing_type,
        int field_number,
        FileDescriptorProto * output)

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 EncodedDescriptorDatabase::FindAllExtensionNumbers(
        const string & extendee_type,
        vector< int > * output)

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.

class DescriptorPoolDatabase: public DescriptorDatabase

#include
namespace google::protobuf

A DescriptorDatabase that fetches files from a given pool.

Members
	DescriptorPoolDatabase(const DescriptorPool & pool)
	~DescriptorPoolDatabase()
implements DescriptorDatabase
virtual bool	FindFileByName(const string & filename, FileDescriptorProto * output) Find a file by file name.  more...
virtual bool	FindFileContainingSymbol(const string & symbol_name, FileDescriptorProto * output) Find the file that declares the given fully-qualified symbol name.  more...
virtual bool	FindFileContainingExtension(const string & containing_type, int field_number, FileDescriptorProto * output) Find the file which defines an extension extending the given message type with the given field number.  more...
virtual bool	FindAllExtensionNumbers(const string & extendee_type, vector< int > * output) Finds the tag numbers used by all known extensions of extendee_type, and appends them to output in an undefined order. more...

---

virtual bool DescriptorPoolDatabase::FindFileByName(
        const string & filename,
        FileDescriptorProto * output)

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 DescriptorPoolDatabase::FindFileContainingSymbol(
        const string & symbol_name,
        FileDescriptorProto * output)

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 DescriptorPoolDatabase::FindFileContainingExtension(
        const string & containing_type,
        int field_number,
        FileDescriptorProto * output)

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 DescriptorPoolDatabase::FindAllExtensionNumbers(
        const string & extendee_type,
        vector< int > * output)

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.

class MergedDescriptorDatabase: public DescriptorDatabase

#include
namespace google::protobuf

A DescriptorDatabase that wraps two or more others.

It first searches the first database and, if that fails, tries the second, and so on.

Members
	MergedDescriptorDatabase(DescriptorDatabase * source1, DescriptorDatabase * source2) Merge just two databases. The sources remain property of the caller.
	MergedDescriptorDatabase(const vector< DescriptorDatabase * > & sources) Merge more than two databases.  more...
	~MergedDescriptorDatabase()
implements DescriptorDatabase
virtual bool	FindFileByName(const string & filename, FileDescriptorProto * output) Find a file by file name.  more...
virtual bool	FindFileContainingSymbol(const string & symbol_name, FileDescriptorProto * output) Find the file that declares the given fully-qualified symbol name.  more...
virtual bool	FindFileContainingExtension(const string & containing_type, int field_number, FileDescriptorProto * output) Find the file which defines an extension extending the given message type with the given field number.  more...
virtual bool	FindAllExtensionNumbers(const string & extendee_type, vector< int > * output) Merges the results of calling all databases.  more...

---

MergedDescriptorDatabase::MergedDescriptorDatabase(
        const vector< DescriptorDatabase * > & sources)

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.

---

virtual bool MergedDescriptorDatabase::FindFileByName(
        const string & filename,
        FileDescriptorProto * output)

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 MergedDescriptorDatabase::FindFileContainingSymbol(
        const string & symbol_name,
        FileDescriptorProto * output)

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 MergedDescriptorDatabase::FindFileContainingExtension(
        const string & containing_type,
        int field_number,
        FileDescriptorProto * output)

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 MergedDescriptorDatabase::FindAllExtensionNumbers(
        const string & extendee_type,
        vector< int > * output)

Merges the results of calling all databases.

Returns true iff any of the databases returned true.