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author | Jon Bratseth <bratseth@yahoo-inc.com> | 2016-06-15 23:09:44 +0200 |
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committer | Jon Bratseth <bratseth@yahoo-inc.com> | 2016-06-15 23:09:44 +0200 |
commit | 72231250ed81e10d66bfe70701e64fa5fe50f712 (patch) | |
tree | 2728bba1131a6f6e5bdf95afec7d7ff9358dac50 /fsa/src/vespa/fsamanagers/metadatahandle.h |
Publish
Diffstat (limited to 'fsa/src/vespa/fsamanagers/metadatahandle.h')
-rw-r--r-- | fsa/src/vespa/fsamanagers/metadatahandle.h | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/fsa/src/vespa/fsamanagers/metadatahandle.h b/fsa/src/vespa/fsamanagers/metadatahandle.h new file mode 100644 index 00000000000..8603caedfb7 --- /dev/null +++ b/fsa/src/vespa/fsamanagers/metadatahandle.h @@ -0,0 +1,130 @@ +// Copyright 2016 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root. +/** + * @author Peter Boros + * @date 2004/10/01 + * @version $Id$ + * @file metadatamanager.h + * @brief Metadata handle class definition. + * + */ + +#pragma once + +#include <string> + +#include "refcountable.h" +#include <vespa/fsa/metadata.h> + +namespace fsa { + +// {{{ class MetaData::Handle + +/** + * @class Handle + * @brief MetaData handle. + * + * A Handle looks like a MetaData, but copies are cheap; the actual + * MetaData objects are refcounted and Handle copies merely copy the + * MetaData pointer and increment the refcount. + */ +class MetaData::Handle { + +private: + + /** + * @brief Unimplemented private default constructor. + */ + Handle(); + /** + * @brief Unimplemented private assignment operator. + */ + Handle& operator=(const Handle&); + + class RefCountableMetaData: public MetaData, public RefCountable<MetaData> { + public: + RefCountableMetaData(const char *datafile, FileAccessMethod fam = FILE_ACCESS_UNDEF) : MetaData(datafile,fam) {} + }; + + RefCountableMetaData *_metaData; /**< The MetaData object itself. */ + +public: + + /** + * @brief Copy constructor. + * + * Duplicate a handle (and add new reference to the MetaData object. + * + * @param h Reference to existing Metadata::Handle. + */ + Handle(const Handle& h) : _metaData(h._metaData) + { + _metaData->addReference(); + } + + /** + * @brief Constructor. + * + * Create a new MetaData object (loaded from file) and add reference. + * + * @param datafile Name of the file containing the metadata. + * @param fam File access mode (read or mmap). If not set, the + * global preferred access mode will be used. + */ + Handle(const char *datafile, FileAccessMethod fam = FILE_ACCESS_UNDEF) : + _metaData(new RefCountableMetaData(datafile,fam)) + { + _metaData->addReference(); + } + + /** + * @brief Constructor. + * + * Create a new MetaData object (loaded from file) and add reference. + * + * @param datafile Name of the file containing the metadata. + * @param fam File access mode (read or mmap). If not set, the + * global preferred access mode will be used. + */ + Handle(const std::string &datafile, FileAccessMethod fam = FILE_ACCESS_UNDEF) : + _metaData(new RefCountableMetaData(datafile.c_str(),fam)) + { + _metaData->addReference(); + } + + /** + * @brief Destructor. + */ + ~Handle(void) + { + _metaData->removeReference(); + } + + /** + * @brief Dereference operator, provides access to Metadata + * methods. + * + * @return Reference to the Metadata object. + */ + const MetaData& operator*() const { return *_metaData; } + + /** + * @brief Dereference operator, provides access to Metadata + * methods. + * + * @return Pointer the Metadata object. + */ + const MetaData* operator->() const { return _metaData; } + + /** + * @brief Proxy methods + */ + uint32_t user(unsigned int idx) const + { + return _metaData->user(idx); + } +}; + +// }}} + +} // namespace fsa + |