/* * Copyright (C) 1996-2023 The Squid Software Foundation and contributors * * Squid software is distributed under GPLv2+ license and includes * contributions from numerous individuals and organizations. * Please see the COPYING and CONTRIBUTORS files for details. */ #ifndef SQUID_SRC_BASE_HERE_H #define SQUID_SRC_BASE_HERE_H #include /// source code location of the caller #define Here() SourceLocation(__func__, __FILE__, __LINE__) /// semi-uniquely identifies a source code location; stable across Squid runs typedef uint32_t SourceLocationId; /// returns a hash of a file name typedef SourceLocationId FileNameHasher(const char *fileName); /// a caching proxy for `hasher` results typedef SourceLocationId FileNameHashCacher(const char *fileName, FileNameHasher hasher); static FileNameHashCacher UnitFileNameHashCacher; /// a source code location that is cheap to create, copy, and store class SourceLocation { public: SourceLocation(const char *aContext, const char *aFileName, const int aLineNo): context(aContext), fileName(aFileName), lineNo(aLineNo), fileNameHashCacher(&UnitFileNameHashCacher) {} /// \returns our location identifier SourceLocationId id() const; /// describes location using a compact but human-friendly format std::ostream &print(std::ostream &os) const; const char *context; ///< line-independent location description const char *fileName; ///< source file name, often relative to build path int lineNo; ///< line number inside the source file name (if positive) private: SourceLocationId calculateId(FileNameHasher) const; FileNameHashCacher *fileNameHashCacher; }; inline std::ostream & operator <<(std::ostream &os, const SourceLocation &location) { return location.print(os); } /// SourceLocation::id() speed optimization hack: Caches `hasher` results. The /// cache capacity is one filename hash. Each translation unit gets one cache. static SourceLocationId UnitFileNameHashCacher(const char *fileName, FileNameHasher hasher) { static SourceLocationId cachedHash = 0; static const char *hashedFilename = nullptr; // Each file #included in a translation unit has its own __FILE__ value. // Keep the cache fresh (and the result correct). if (hashedFilename != fileName) { // cheap pointer comparison hashedFilename = fileName; cachedHash = hasher(fileName); } return cachedHash; } #endif /* SQUID_SRC_BASE_HERE_H */