PTLib  Version 2.10.11
PStructuredFile Class Reference

A class representing a a structured file that is portable accross CPU architectures (as in the XDR protocol). More...

#include <sfile.h>

Inheritance diagram for PStructuredFile:
PFile PChannel PObject

Classes

struct  Element
 Elements in the structure definition. More...
 

Public Member Functions

Construction
 PStructuredFile ()
 Create a structured file object but do not open it. More...
 
 PStructuredFile (OpenMode mode, int opts=ModeDefault)
 Create a unique temporary file name, and open the file in the specified mode and using the specified options. More...
 
 PStructuredFile (const PFilePath &name, OpenMode mode=ReadWrite, int opts=ModeDefault)
 Create a structured file object with the specified name and open it in the specified mode and with the specified options. More...
 
Structured I/O functions
PBoolean Read (void *buffer)
 Read a sequence of bytes into the specified buffer, translating the structure according to the specification made in the SetStructure() function. More...
 
PBoolean Write (const void *buffer)
 Write a sequence of bytes into the specified buffer, translating the structure according to the specification made in the SetStructure() function. More...
 
- Public Member Functions inherited from PFile
Comparison Compare (const PObject &obj) const
 Determine the relative rank of the two objects. More...
 
virtual PString GetName () const
 Get the platform and I/O channel type name of the channel. More...
 
virtual PBoolean Close ()
 Close the file channel. More...
 
 PFile ()
 Create a file object but do not open it. More...
 
 PFile (OpenMode mode, int opts=ModeDefault)
 Create a unique temporary file name, and open the file in the specified mode and using the specified options. More...
 
 PFile (const PFilePath &name, OpenMode mode=ReadWrite, int opts=ModeDefault)
 Create a file object with the specified name and open it in the specified mode and with the specified options. More...
 
 ~PFile ()
 Close the file on destruction. More...
 
PBoolean Exists () const
 Check for file existance. More...
 
PBoolean Access (OpenMode mode)
 Check for file access modes. More...
 
PBoolean Remove (PBoolean force=false)
 Delete the current file. More...
 
PBoolean Rename (const PString &newname, PBoolean force=false)
 Change the current files name. More...
 
PBoolean Copy (const PFilePath &newname, PBoolean force=false)
 Make a copy of the current file. More...
 
PBoolean Move (const PFilePath &newname, PBoolean force=false)
 Move the current file. More...
 
const PFilePathGetFilePath () const
 Get the full path name of the file. More...
 
void SetFilePath (const PString &path)
 Set the full path name of the file. More...
 
virtual PBoolean Open (OpenMode mode=ReadWrite, int opts=ModeDefault)
 Open the current file in the specified mode and with the specified options. More...
 
virtual PBoolean Open (const PFilePath &name, OpenMode mode=ReadWrite, int opts=ModeDefault)
 Open the specified file name in the specified mode and with the specified options. More...
 
virtual off_t GetLength () const
 Get the current size of the file. More...
 
virtual PBoolean SetLength (off_t len)
 Set the size of the file, padding with 0 bytes if it would require expanding the file, or truncating it if being made shorter. More...
 
virtual PBoolean SetPosition (off_t pos, FilePositionOrigin origin=Start)
 Set the current active position in the file for the next read or write operation. More...
 
virtual off_t GetPosition () const
 Get the current active position in the file for the next read or write operation. More...
 
PBoolean IsEndOfFile () const
 Determine if the current file position is at the end of the file. More...
 
PBoolean GetInfo (PFileInfo &info)
 Get information (eg protection, timestamps) on the current file. More...
 
PBoolean SetPermissions (int permissions)
 Set permissions on the current file. More...
 
- Public Member Functions inherited from PChannel
PBoolean SetErrorValues (Errors errorCode, int osError, ErrorGroup group=LastGeneralError)
 Set error values to those specified. More...
 
 PChannel ()
 Create the channel. More...
 
 ~PChannel ()
 Close down the channel. More...
 
virtual PINDEX HashFunction () const
 Calculate a hash value for use in sets and dictionaries. More...
 
virtual PBoolean IsOpen () const
 Determine if the channel is currently open. More...
 
int GetHandle () const
 Get the integer operating system handle for the channel. More...
 
virtual PChannelGetBaseReadChannel () const
 Get the base channel of channel indirection using PIndirectChannel. More...
 
virtual PChannelGetBaseWriteChannel () const
 Get the base channel of channel indirection using PIndirectChannel. More...
 
void SetReadTimeout (const PTimeInterval &time)
 Set the timeout for read operations. More...
 
PTimeInterval GetReadTimeout () const
 Get the timeout for read operations. More...
 
virtual PINDEX GetLastReadCount () const
 Get the number of bytes read by the last Read() call. More...
 
virtual int ReadChar ()
 Read a single 8 bit byte from the channel. More...
 
PBoolean ReadBlock (void *buf, PINDEX len)
 Read len bytes into the buffer from the channel. More...
 
PString ReadString (PINDEX len)
 Read len character into a string from the channel. More...
 
virtual PBoolean ReadAsync (void *buf, PINDEX len)
 Begin an asynchronous read from channel. More...
 
virtual void OnReadComplete (void *buf, PINDEX len)
 User callback function for when a ReadAsync() call has completed or timed out. More...
 
void SetWriteTimeout (const PTimeInterval &time)
 Set the timeout for write operations to complete. More...
 
PTimeInterval GetWriteTimeout () const
 Get the timeout for write operations to complete. More...
 
virtual PBoolean Write (const void *buf, PINDEX len, const void *mark)
 Low level write to the channel with marker. More...
 
virtual PINDEX GetLastWriteCount () const
 Get the number of bytes written by the last Write() call. More...
 
PBoolean WriteChar (int c)
 Write a single character to the channel. More...
 
PBoolean WriteString (const PString &str)
 Write a string to the channel. More...
 
virtual PBoolean WriteAsync (const void *buf, PINDEX len)
 Begin an asynchronous write from channel. More...
 
virtual void OnWriteComplete (const void *buf, PINDEX len)
 User callback function for when a WriteAsync() call has completed or timed out. More...
 
virtual PBoolean Shutdown (ShutdownValue option)
 Close one or both of the data streams associated with a channel. More...
 
virtual bool SetLocalEcho (bool localEcho)
 Set local echo mode. More...
 
virtual bool FlowControl (const void *flowData)
 Flow Control information Pass data to the channel for flowControl determination. More...
 
PBoolean SetBufferSize (PINDEX newSize)
 Set the iostream buffer size for reads and writes. More...
 
PBoolean SendCommandString (const PString &command)
 Send a command meta-string. More...
 
void AbortCommandString ()
 Abort a command string that is in progress. More...
 
Errors GetErrorCode (ErrorGroup group=NumErrorGroups) const
 Get normalised error code. More...
 
int GetErrorNumber (ErrorGroup group=NumErrorGroups) const
 Get OS errro code. More...
 
virtual PString GetErrorText (ErrorGroup group=NumErrorGroups) const
 Get error message description. More...
 
virtual PBoolean Read (const VectorOfSlice &slices)
 Low level scattered read from the channel. More...
 
virtual PBoolean Write (const VectorOfSlice &slices)
 Low level scattered write to the channel. More...
 
- Public Member Functions inherited from PObject
virtual ~PObject ()
 
virtual PObjectClone () const
 Create a copy of the class on the heap. More...
 
virtual const char * GetClass (unsigned ancestor=0) const
 Get the current dynamic type of the object instance. More...
 
PBoolean IsClass (const char *cls) const
 
virtual PBoolean InternalIsDescendant (const char *clsName) const
 Determine if the dynamic type of the current instance is a descendent of the specified class. More...
 
virtual Comparison CompareObjectMemoryDirect (const PObject &obj) const
 Determine the byte wise comparison of two objects. More...
 
bool operator== (const PObject &obj) const
 Compare the two objects. More...
 
bool operator!= (const PObject &obj) const
 Compare the two objects. More...
 
bool operator< (const PObject &obj) const
 Compare the two objects. More...
 
bool operator> (const PObject &obj) const
 Compare the two objects. More...
 
bool operator<= (const PObject &obj) const
 Compare the two objects. More...
 
bool operator>= (const PObject &obj) const
 Compare the two objects. More...
 
virtual void PrintOn (ostream &strm) const
 Output the contents of the object to the stream. More...
 
virtual void ReadFrom (istream &strm)
 Input the contents of the object from the stream. More...
 

Protected Attributes

PINDEX structureSize
 Number of bytes in structure. More...
 
Elementstructure
 Array of elements in the structure. More...
 
PINDEX numElements
 Number of elements in the array. More...
 
- Protected Attributes inherited from PFile
PFilePath path
 The fully qualified path name for the file. More...
 
PBoolean removeOnClose
 File is to be removed when closed. More...
 
- Protected Attributes inherited from PChannel
int os_handle
 The operating system file handle return by standard open() function. More...
 
Errors lastErrorCode [NumErrorGroups+1]
 The platform independant error code. More...
 
int lastErrorNumber [NumErrorGroups+1]
 The operating system error number (eg as returned by errno). More...
 
PINDEX lastReadCount
 Number of byte last read by the Read() function. More...
 
PINDEX lastWriteCount
 Number of byte last written by the Write() function. More...
 
PTimeInterval readTimeout
 Timeout for read operations. More...
 
PTimeInterval writeTimeout
 Timeout for write operations. More...
 
PString channelName
 
PMutex px_threadMutex
 
PXBlockType px_lastBlockType
 
PThreadpx_readThread
 
PThreadpx_writeThread
 
PMutex px_writeMutex
 
PThreadpx_selectThread [3]
 
PMutex px_selectMutex [3]
 

Structure definition functions

enum  ElementType {
  Character, Integer16, Integer32, Integer64,
  Float32, Float64, Float80, NumElementTypes
}
 All element types in a structure. More...
 
PINDEX GetStructureSize ()
 Get the size of each structure in the file. More...
 
void SetStructure (Element *structure, PINDEX numElements)
 Set the structure of each record in the file. More...
 

Additional Inherited Members

- Public Types inherited from PFile
enum  OpenMode { ReadOnly, WriteOnly, ReadWrite }
 When a file is opened, it may restrict the access available to operations on the object instance. More...
 
enum  OpenOptions {
  ModeDefault = -1, MustExist = 0, Create = 1, Truncate = 2,
  Exclusive = 4, Temporary = 8, DenySharedRead = 16, DenySharedWrite = 32
}
 When a file is opened, a number of options may be associated with the open file. More...
 
enum  FilePositionOrigin { Start = SEEK_SET, Current = SEEK_CUR, End = SEEK_END }
 Options for the origin in setting the file position. More...
 
- Public Types inherited from PChannel
enum  PXBlockType { PXReadBlock, PXWriteBlock, PXAcceptBlock, PXConnectBlock }
 
enum  ShutdownValue { ShutdownRead = 0, ShutdownWrite = 1, ShutdownReadAndWrite = 2 }
 
enum  Errors {
  NoError, NotFound, FileExists, DiskFull,
  AccessDenied, DeviceInUse, BadParameter, NoMemory,
  NotOpen, Timeout, Interrupted, BufferTooSmall,
  Miscellaneous, ProtocolFailure, NumNormalisedErrors
}
 Normalised error codes. More...
 
enum  ErrorGroup { LastReadError, LastWriteError, LastGeneralError, NumErrorGroups }
 Error groups. More...
 
typedef std::vector< SliceVectorOfSlice
 
- Public Types inherited from PObject
enum  Comparison { LessThan = -1, EqualTo = 0, GreaterThan = 1 }
 Result of the comparison operation performed by the Compare() function. More...
 
- Static Public Member Functions inherited from PFile
static PBoolean Exists (const PFilePath &name)
 Check for file existance. More...
 
static PBoolean Access (const PFilePath &name, OpenMode mode)
 Check for file access modes. More...
 
static PBoolean Remove (const PFilePath &name, PBoolean force=false)
 Delete the specified file. More...
 
static PBoolean Remove (const PString &name, PBoolean force=false)
 
static PBoolean Rename (const PFilePath &oldname, const PString &newname, PBoolean force=false)
 Change the specified files name. More...
 
static PBoolean Copy (const PFilePath &oldname, const PFilePath &newname, PBoolean force=false)
 Make a copy of the specified file. More...
 
static PBoolean Move (const PFilePath &oldname, const PFilePath &newname, PBoolean force=false)
 Move the specified file. More...
 
static PBoolean GetInfo (const PFilePath &name, PFileInfo &info)
 Get information (eg protection, timestamps) on the specified file. More...
 
static PBoolean SetPermissions (const PFilePath &name, int permissions)
 Set permissions on the specified file. More...
 
- Static Public Member Functions inherited from PChannel
static PBoolean ConvertOSError (int libcReturnValue, Errors &lastError, int &osError)
 Convert an operating system error into platform independent error. More...
 
static PString GetErrorText (Errors lastError, int osError=0)
 Get error message description. More...
 
- Static Public Member Functions inherited from PObject
static const char * Class ()
 Get the name of the class as a C string. More...
 
static Comparison InternalCompareObjectMemoryDirect (const PObject *obj1, const PObject *obj2, PINDEX size)
 Internal function caled from CompareObjectMemoryDirect() More...
 
- Protected Member Functions inherited from PChannel
 PChannel (const PChannel &)
 
PChanneloperator= (const PChannel &)
 
virtual PBoolean ConvertOSError (int libcReturnValue, ErrorGroup group=LastGeneralError)
 Convert an operating system error into platform independent error. More...
 
int ReadCharWithTimeout (PTimeInterval &timeout)
 Read a character with specified timeout. More...
 
PBoolean ReceiveCommandString (int nextChar, const PString &reply, PINDEX &pos, PINDEX start)
 
PBoolean PXSetIOBlock (PXBlockType type, const PTimeInterval &timeout)
 
int PXClose ()
 
- Protected Member Functions inherited from PObject
 PObject ()
 Constructor for PObject, made protected so cannot ever create one on its own. More...
 

Detailed Description

A class representing a a structured file that is portable accross CPU architectures (as in the XDR protocol).

This differs from object serialisation in that the access is always to a disk file and is random access. It would primarily be used for database type applications.

Member Enumeration Documentation

§ ElementType

All element types in a structure.

Enumerator
Character 

Element is a single character.

Integer16 

Element is a 16 bit integer.

Integer32 

Element is a 32 bit integer.

Integer64 

Element is a 64 bit integer.

Float32 

Element is a 32 bit IEE floating point number.

Float64 

Element is a 64 bit IEE floating point number.

Float80 

Element is a 80 bit IEE floating point number.

NumElementTypes 

Constructor & Destructor Documentation

§ PStructuredFile() [1/3]

PStructuredFile::PStructuredFile ( )

Create a structured file object but do not open it.

It does not initially have a valid file name. However, an attempt to open the file using the PFile::Open() function will generate a unique temporary file.

The initial structure size is one byte.

§ PStructuredFile() [2/3]

PStructuredFile::PStructuredFile ( OpenMode  mode,
int  opts = ModeDefault 
)

Create a unique temporary file name, and open the file in the specified mode and using the specified options.

Note that opening a new, unique, temporary file name in ReadOnly mode will always fail. This would only be usefull in a mode and options that will create the file.

The PChannel::IsOpen() function may be used after object construction to determine if the file was successfully opened.

Parameters
modeMode in which to open the file.
optsOpenOptions enum# for open operation.

§ PStructuredFile() [3/3]

PStructuredFile::PStructuredFile ( const PFilePath name,
OpenMode  mode = ReadWrite,
int  opts = ModeDefault 
)

Create a structured file object with the specified name and open it in the specified mode and with the specified options.

The PChannel::IsOpen() function may be used after object construction to determine if the file was successfully opened.

Parameters
nameName of file to open.
modeMode in which to open the file.
optsOpenOptions enum# for open operation.

Member Function Documentation

§ GetStructureSize()

PINDEX PStructuredFile::GetStructureSize ( )
inline

Get the size of each structure in the file.

Returns
number of bytes in a structure.

References structureSize.

§ Read()

PBoolean PStructuredFile::Read ( void *  buffer)

Read a sequence of bytes into the specified buffer, translating the structure according to the specification made in the SetStructure() function.

Returns
true if the structure was successfully read.
Parameters
bufferPointer to structure to receive data.

§ SetStructure()

void PStructuredFile::SetStructure ( Element structure,
PINDEX  numElements 
)

Set the structure of each record in the file.

Parameters
structureArray of structure elements
numElementsNumber of structure elements in structure.

§ Write()

PBoolean PStructuredFile::Write ( const void *  buffer)

Write a sequence of bytes into the specified buffer, translating the structure according to the specification made in the SetStructure() function.

Returns
true if the structure was successfully written.
Parameters
bufferPointer to structure to write data from.

Member Data Documentation

§ numElements

PINDEX PStructuredFile::numElements
protected

Number of elements in the array.

§ structure

Element* PStructuredFile::structure
protected

Array of elements in the structure.

§ structureSize

PINDEX PStructuredFile::structureSize
protected

Number of bytes in structure.

Referenced by GetStructureSize().


The documentation for this class was generated from the following file: