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#include <boost/tr1/memory.hpp>
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* Struct for wrapping the basic <code>FILE</code> locked functions for
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* reading and writing defined in <code>stdio.h</code>.
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static inline void configure(FILE *file_ptr)
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static inline size_t fwrite(const void *ptr, size_t size, size_t count, FILE *file_ptr)
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return ::fwrite(ptr, size, count, file_ptr);
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static inline size_t fread(void * ptr, size_t size, size_t count, FILE *file_ptr)
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return ::fread(ptr, size, count, file_ptr);
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static inline int fgetc(FILE *file_ptr)
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return ::fgetc(file_ptr);
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static inline int fputc(int c, FILE *file_ptr)
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return ::fputc(c, file_ptr);
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* Struct for wrapping the basic <code>FILE</code> unlocked functions for
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* reading and writing defined in <code>stdio_exts.h</code>.
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static inline void configure(FILE *file_ptr)
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__fsetlocking(file_ptr, FSETLOCKING_BYCALLER);
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static inline size_t fwrite(const void *ptr, size_t size, size_t count, FILE *file_ptr)
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return ::fwrite_unlocked(ptr, size, count, file_ptr);
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static inline size_t fread(void * ptr, size_t size, size_t count, FILE *file_ptr)
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return ::fread_unlocked(ptr, size, count, file_ptr);
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static inline int fgetc(FILE *file_ptr)
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return ::fgetc_unlocked(file_ptr);
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static inline int fputc(int c, FILE *file_ptr)
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return ::fputc_unlocked(c, file_ptr);
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* This is a wrapper class for the <code>FILE</code> functions that
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* provides all the functionality to handle files safely. It is defined
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* as a template in order to allow to use either the locked or the
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* unlocked API, by means of the structs <code>LockedAccess</code> and
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* <code>UnlockedAccess</code>. The unlocked API is not thread-safe,
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* but it provides faster file operations.
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* @see UnlockedAccess
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template<class IO> class BaseFile
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* Safe pointer to this class.
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typedef tr1::shared_ptr< BaseFile<IO> > Ptr;
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* Initialized the internal file pointer to <code>NULL</code>.
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* Returns <code>true</code> if the given file exists. This
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* is a wrapper of the system funcion <code>stat</code>.
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static bool Exists(const char *file_name)
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struct stat file_stat;
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return (stat(file_name, &file_stat) == 0);
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* Opens a file with a specific access mode.
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* @param file_name Path name of the file to open.
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* @param access Access mode as a <code>fopen</code>
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* compatible format string.
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* @return <code>true</code> if successful.
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bool Open(const char *file_name, const char *access)
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assert(file_ptr == NULL);
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if((file_ptr = fopen(file_name, access)) == NULL) return false;
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IO::configure(file_ptr);
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* Opens a file with a specific access mode.
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* @param file_name Path name of the file to open.
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* @param access Access mode as a <code>fopen</code>
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* compatible format string.
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* @return <code>true</code> if successful.
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bool Open(const string& file_name, const char *access)
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return Open(file_name.c_str(), access);
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* Opens a file with a specific access mode given an already
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* opened <code>File</code> object. The descriptor of the opened
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* file is duplicated and re-opened with the access mode given.
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* @param file Opened file.
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* @param access Access mode as a <code>fopen</code>
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* compatible format string.
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* @return <code>true</code> if successful.
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template<class IO2> bool Open(const BaseFile<IO2>& file, const char *access)
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assert((file_ptr == NULL) && file.IsValid());
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if((new_fd = dup(file.GetDescriptor())) < 0) return false;
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if((file_ptr = fdopen(new_fd, access)) == NULL) {
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IO::configure(file_ptr);
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* Calls the function <code>Open</code> with the <code>"rb"
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* </code> access mode (reading).
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bool OpenForReading(const char *file_name)
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return Open(file_name, "rb");
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* Calls the function <code>Open</code> with the <code>"rb"
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* </code> access mode (reading).
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bool OpenForReading(const string& file_name)
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return Open(file_name.c_str(), "rb");
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* Calls the function <code>Open</code> with the <code>"rb"
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* </code> access mode (reading).
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template<class IO2> bool OpenForReading(const BaseFile<IO2>& file)
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return Open(file, "rb");
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* Calls the function <code>Open</code> with the <code>"wb"
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* </code> access mode (writing).
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bool OpenForWriting(const char *file_name)
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return Open(file_name, "wb");
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* Calls the function <code>Open</code> with the <code>"wb"
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* </code> access mode (writing).
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bool OpenForWriting(const string& file_name)
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return Open(file_name.c_str(), "wb");
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* Calls the function <code>Open</code> with the <code>"wb"
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* </code> access mode (writing).
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template<class IO2> bool OpenForWriting(const BaseFile<IO2>& file)
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return Open(file, "wb");
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* Changes the current position of the file.
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* @param offset Offset to add to the current position.
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* @param origin Origin to use for the change (<code>
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* SEEK_SET</code> by default).
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* @return <code>true</code> if successful.
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bool Seek(int offset, int origin = SEEK_SET) const
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assert(file_ptr != NULL);
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return !fseek(file_ptr, offset, origin);
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if(file_ptr != NULL) {
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* Returns the current file position.
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uint64_t GetOffset() const
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assert(file_ptr != NULL);
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return ftell(file_ptr);
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* Returns the EOF status (<code>feof</code>) of the file.
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assert(file_ptr != NULL);
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return feof(file_ptr);
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* Returns the file descriptor.
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int GetDescriptor() const
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assert(file_ptr != NULL);
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return fileno(file_ptr);
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* Return the current size of the file, without modifying
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uint64_t GetSize() const
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assert(file_ptr != NULL);
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uint64_t offset = GetOffset();
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uint64_t final_offset = GetOffset();
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Seek(offset, SEEK_SET);
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* Reads a byte from the file.
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assert(file_ptr != NULL);
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return IO::fgetc(file_ptr);
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* Reads a value from the file.
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* @param value Pointer to the value where to store.
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* @param num_bytes Number of bytes to read (by default,
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* the size of the value).
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* @return <code>true</code> if successful.
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template<typename T> bool Read(T *value, int num_bytes = sizeof(T)) const
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assert(file_ptr != NULL);
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return (IO::fread((void *) value, num_bytes, 1, file_ptr) == 1);
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* Reads a value from the file in reverse order.
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* @param value Pointer to the value where to store.
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* @param num_bytes Number of bytes to read (by default,
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* the size of the value).
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* @return <code>true</code> if successful.
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template<typename T> bool ReadReverse(T *value, int num_bytes = sizeof(T)) const
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assert(file_ptr != NULL);
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for (char *ptr = ((char *) value) + (num_bytes - 1); num_bytes-- > 0; ptr--)
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if (IO::fread((void *) ptr, 1, 1, file_ptr) != 1) return false;
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* Writes a byte to the file.
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int WriteByte(int c) const
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assert(file_ptr != NULL);
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return IO::fputc(c, file_ptr);
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* Writes a value to the file.
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* @param value Pointer to the value.
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* @param num_bytes Number of bytes to write (by default,
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* the size of the value).
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* @return <code>true</code> if successful.
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template<typename T> bool Write(T *value, int num_bytes = sizeof(T)) const
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assert(file_ptr != NULL);
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return (IO::fwrite((void *) value, num_bytes, 1, file_ptr) == 1);
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* Writes a value to the file in reverse order.
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* @param value Pointer to the value.
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* @param num_bytes Number of bytes to write (by default,
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* the size of the value).
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* @return <code>true</code> if successful.
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template<typename T> bool WriteReverse(T *value, int num_bytes = sizeof(T)) const
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assert(file_ptr != NULL);
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for (char *ptr = ((char *) value) + (num_bytes - 1); num_bytes-- > 0; ptr--)
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if (IO::fwrite((void *) ptr, 1, 1, file_ptr) != 1) return false;
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* Returns <code>true</code> if the file pointer is not
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return (file_ptr != NULL);
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* Returns <code>true</code> if the file pointer is not
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operator bool() const
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return (file_ptr != NULL);
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* The destructor closes the file.
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* Specialization of the class <code>BaseFile</code> with
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typedef BaseFile<LockedAccess> File;
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* Specialization of the class <code>BaseFile</code> with
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* @see UnlockedAccess
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#ifndef _NO_FAST_FILE
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typedef BaseFile<UnlockedAccess> FastFile;
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#endif /* _DATA_FILE_H_ */
added
removed
src/data/file.h
