Steinberg::MemoryStream Class Reference

#include <memorystream.h>

Inheritance diagram for Steinberg::MemoryStream:

Collaboration diagram for Steinberg::MemoryStream:

Public Member Functions
	MemoryStream ()
	MemoryStream (void *memory, TSize memorySize)
	reuse a given memory without getting ownership More...
virtual	~MemoryStream ()
tresult PLUGIN_API	read (void *buffer, int32 numBytes, int32 *numBytesRead) SMTG_OVERRIDE
tresult PLUGIN_API	write (void *buffer, int32 numBytes, int32 *numBytesWritten) SMTG_OVERRIDE
tresult PLUGIN_API	seek (int64 pos, int32 mode, int64 *result) SMTG_OVERRIDE
tresult PLUGIN_API	tell (int64 *pos) SMTG_OVERRIDE
TSize	getSize () const
	returns the current memory size More...
void	setSize (TSize size)
	set the memory size, a realloc will occur if memory already used More...
char *	getData () const
	returns the memory pointer More...
char *	detachData ()
	returns the memory pointer and give up ownership More...
bool	truncate ()
	realloc to the current use memory size if needed More...
bool	truncateToCursor ()
	truncate memory at current cursor position More...

Protected Attributes
char *	memory
TSize	memorySize
TSize	size
int64	cursor
bool	ownMemory
bool	allocationError

Detailed Description

Memory based Stream for IBStream implementation (using malloc).

Definition at line 47 of file lib-vst3/memorystream.h.

Constructor & Destructor Documentation

MemoryStream() [1/2]

MemoryStream::MemoryStream

(

)

Definition at line 60 of file lib-vst3/memorystream.cpp.

: memory (nullptr)
, memorySize (0)
, size (0)
, cursor (0)
, ownMemory (true)
, allocationError (false)
{
   FUNKNOWN_CTOR
}

MemoryStream() [2/2]

MemoryStream::MemoryStream	(	void *	memory,
		TSize	memorySize
	)

reuse a given memory without getting ownership

Definition at line 48 of file lib-vst3/memorystream.cpp.

: memory ((char*)data)
, memorySize (length)
, size (length)
, cursor (0)
, ownMemory (false)
, allocationError (false)
{ 
   FUNKNOWN_CTOR 
}

~MemoryStream()

MemoryStream::~MemoryStream ( )

virtual

Definition at line 72 of file lib-vst3/memorystream.cpp.

{ 
   if (ownMemory && memory)
      ::free (memory);
 
   FUNKNOWN_DTOR 
}

References staffpad::vo::free(), memory, and ownMemory.

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Member Function Documentation

detachData()

char * MemoryStream::detachData

(

)

returns the memory pointer and give up ownership

Definition at line 267 of file lib-vst3/memorystream.cpp.

{
   if (ownMemory)
   {
      char* result = memory;
      memory = nullptr;
      memorySize = 0;
      size = 0;
      cursor = 0;
      return result;
   }
   return nullptr;
}

References cursor, memory, memorySize, ownMemory, and size.

getData()

char * MemoryStream::getData

(

)

const

returns the memory pointer

Definition at line 261 of file lib-vst3/memorystream.cpp.

{
   return memory;
}

References memory.

getSize()

TSize MemoryStream::getSize

(

)

const

returns the current memory size

Definition at line 190 of file lib-vst3/memorystream.cpp.

{
   return size;
}

References size.

read()

tresult PLUGIN_API MemoryStream::read	(	void *	buffer,
		int32	numBytes,
		int32 *	numBytesRead
	)

Definition at line 81 of file lib-vst3/memorystream.cpp.

{
   if (memory == nullptr)
   {
      if (allocationError)
         return kOutOfMemory;
      numBytes = 0;
   }
   else
   {     
      // Does read exceed size ?
      if (cursor + numBytes > size)
      {
         int32 maxBytes = int32 (size - cursor);
 
         // Has length become zero or negative ?
         if (maxBytes <= 0) 
         {
            cursor = size;
            numBytes = 0;
         }
         else
            numBytes = maxBytes;
      }
      
      if (numBytes)
      {
         memcpy (data, &memory[cursor], static_cast<size_t> (numBytes));
         cursor += numBytes;
      }
   }
 
   if (numBytesRead)
      *numBytesRead = numBytes;
 
   return kResultTrue;
}

References allocationError, cursor, memory, and size.

seek()

tresult PLUGIN_API MemoryStream::seek	(	int64	pos,
		int32	mode,
		int64 *	result
	)

Definition at line 154 of file lib-vst3/memorystream.cpp.

{
   switch (mode) 
   {
      case kIBSeekSet:
         cursor = pos;
         break;
      case kIBSeekCur:
         cursor = cursor + pos;
         break;
      case kIBSeekEnd:
         cursor = size + pos;
         break;
   }
 
   if (ownMemory == false)
      if (cursor > memorySize)
         cursor = memorySize;
 
   if (result)
      *result = cursor;
 
   return kResultTrue;
}

References cursor, memorySize, ownMemory, and size.

Referenced by VST3Wrapper::InitializeComponents().

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setSize()

void MemoryStream::setSize

(

TSize

size

)

set the memory size, a realloc will occur if memory already used

Definition at line 196 of file lib-vst3/memorystream.cpp.

{
   if (s <= 0)
   {
      if (ownMemory && memory)
         free (memory);
 
      memory = nullptr;
      memorySize = 0;
      size = 0;
      cursor = 0;
      return;
   }
 
   TSize newMemorySize = (((Max (memorySize, s) - 1) / kMemGrowAmount) + 1) * kMemGrowAmount;
   if (newMemorySize == memorySize)
   {
      size = s;
      return;
   }
 
   if (memory && ownMemory == false)
   {
      allocationError = true;
      return;  
   }
 
   ownMemory = true;
   char* newMemory = nullptr;
 
   if (memory)
   {
      newMemory = (char*)realloc (memory, (size_t)newMemorySize);
      if (newMemory == nullptr && newMemorySize > 0)
      {
         newMemory = (char*)malloc ((size_t)newMemorySize);
         if (newMemory)
         {
            memcpy (newMemory, memory, (size_t)Min (newMemorySize, memorySize));           
            free (memory);
         }     
      }
   }
   else
      newMemory = (char*)malloc ((size_t)newMemorySize);
 
   if (newMemory == nullptr)
   {
      if (newMemorySize > 0)
         allocationError = true;
 
      memory = nullptr;
      memorySize = 0;
      size = 0;
      cursor = 0;
   }
   else
   {
      memory = newMemory;
      memorySize = newMemorySize;
      size = s;
   }
}

References allocationError, cursor, staffpad::vo::free(), Steinberg::kMemGrowAmount, memory, memorySize, ownMemory, and size.

Referenced by write().

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tell()

tresult PLUGIN_API MemoryStream::tell

(

int64 *

pos

)

Definition at line 180 of file lib-vst3/memorystream.cpp.

{
   if (!pos)
      return kInvalidArgument;
 
   *pos = cursor;
   return kResultTrue;
}

References cursor.

truncate()

bool MemoryStream::truncate

(

)

realloc to the current use memory size if needed

Definition at line 282 of file lib-vst3/memorystream.cpp.

{
   if (ownMemory == false)
      return false;
 
   if (memorySize == size)
      return true;
 
   memorySize = size;
   
   if (memorySize == 0)
   {
      if (memory)
      {
         free (memory);
         memory = nullptr;
      }
   }
   else
   {
      if (memory)
      {
         char* newMemory = (char*)realloc (memory, (size_t)memorySize);
         if (newMemory)
            memory = newMemory;
      }
   }
   return true;
}

References staffpad::vo::free(), memory, memorySize, ownMemory, and size.

Referenced by truncateToCursor().

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truncateToCursor()

bool MemoryStream::truncateToCursor

(

)

truncate memory at current cursor position

Definition at line 313 of file lib-vst3/memorystream.cpp.

{
   size = cursor;
   return truncate ();
}

References cursor, size, and truncate().

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write()

tresult PLUGIN_API MemoryStream::write	(	void *	buffer,
		int32	numBytes,
		int32 *	numBytesWritten
	)

Definition at line 120 of file lib-vst3/memorystream.cpp.

{
   if (allocationError)
      return kOutOfMemory;
   if (buffer == nullptr)
      return kInvalidArgument;
 
   // Does write exceed size ?
   TSize requiredSize = cursor + numBytes;
   if (requiredSize > size) 
   {     
      if (requiredSize > memorySize)
         setSize (requiredSize);
      else
         size = requiredSize;
   }
   
   // Copy data
   if (memory && cursor >= 0 && numBytes > 0)
   {
      memcpy (&memory[cursor], buffer, static_cast<size_t> (numBytes));
      // Update cursor
      cursor += numBytes;
   }
   else
      numBytes = 0;
 
   if (numBytesWritten)
      *numBytesWritten = numBytes;
 
   return kResultTrue;
}

References allocationError, cursor, memory, memorySize, setSize(), and size.

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Member Data Documentation

allocationError

bool Steinberg::MemoryStream::allocationError

protected

Definition at line 76 of file lib-vst3/memorystream.h.

Referenced by read(), setSize(), and write().

cursor

int64 Steinberg::MemoryStream::cursor

protected

Definition at line 74 of file lib-vst3/memorystream.h.

Referenced by detachData(), read(), seek(), setSize(), tell(), truncateToCursor(), and write().

memory

char* Steinberg::MemoryStream::memory

protected

Definition at line 71 of file lib-vst3/memorystream.h.

Referenced by detachData(), getData(), read(), setSize(), truncate(), write(), and ~MemoryStream().

memorySize

TSize Steinberg::MemoryStream::memorySize

protected

Definition at line 72 of file lib-vst3/memorystream.h.

Referenced by detachData(), seek(), setSize(), truncate(), and write().

ownMemory

bool Steinberg::MemoryStream::ownMemory

protected

Definition at line 75 of file lib-vst3/memorystream.h.

Referenced by detachData(), seek(), setSize(), truncate(), and ~MemoryStream().

size

TSize Steinberg::MemoryStream::size

protected

Definition at line 73 of file lib-vst3/memorystream.h.

Referenced by detachData(), getSize(), read(), seek(), setSize(), truncate(), truncateToCursor(), and write().

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

• lib-vst3/memorystream.h
• lib-vst3/memorystream.cpp