Note(s): Forbid Copying Idiom 4.1. More...

#include <Buffer.h>

Inheritance diagram for Buffer_Namespace::Buffer:

Collaboration diagram for Buffer_Namespace::Buffer:

Public Member Functions
	Buffer (BufferMgr *bm, BufferList::iterator seg_it, const int device_id, const size_t page_size=512, const size_t num_bytes=0)
	Constructs a Buffer object. The constructor requires a memory address (provided by BufferMgr), number of pages, and the size in bytes of each page. Additionally, the Buffer can be initialized with an epoch. More...

	~Buffer () override
	Destructor. More...

void	read (int8_t *const dst, const size_t num_bytes, const size_t offset=0, const MemoryLevel dst_buffer_type=CPU_LEVEL, const int device_id=-1) override
	Reads (copies) data from the buffer to the destination (dst) memory location. Reads (copies) nbytes of data from the buffer, beginning at the specified byte offset, into the destination (dst) memory location. More...

void	reserve (const size_t num_bytes) override

void	write (int8_t *src, const size_t num_bytes, const size_t offset=0, const MemoryLevel src_buffer_type=CPU_LEVEL, const int device_id=-1) override
	Writes (copies) data from src into the buffer. Writes (copies) nbytes of data into the buffer at the specified byte offset, from the source (src) memory location. More...

void	append (int8_t *src, const size_t num_bytes, const MemoryLevel src_buffer_type=CPU_LEVEL, const int deviceId=-1) override

int8_t *	getMemoryPtr () override
	Returns a raw, constant (read-only) pointer to the underlying buffer. More...

void	setMemoryPtr (int8_t *new_ptr) override

size_t	reservedSize () const override
	Returns the total number of bytes allocated for the buffer. More...

size_t	pageCount () const override
	Returns the number of pages in the buffer. More...

size_t	pageSize () const override
	Returns the size in bytes of each page in the buffer. More...

int	pin () override

int	unPin () override

int	getPinCount () override

int32_t	getSlabNum () const

Public Member Functions inherited from Data_Namespace::AbstractBuffer
	AbstractBuffer (const int device_id)

	AbstractBuffer (const int device_id, const SQLTypeInfo sql_type)

virtual	~AbstractBuffer ()

virtual MemoryLevel	getType () const =0

size_t	size () const

int	getDeviceId () const

bool	isDirty () const

bool	isAppended () const

bool	isUpdated () const

bool	hasEncoder () const

SQLTypeInfo	getSqlType () const

void	setSqlType (const SQLTypeInfo &sql_type)

Encoder *	getEncoder () const

void	setDirty ()

void	setUpdated ()

void	setAppended ()

void	setSize (const size_t size)

void	clearDirtyBits ()

void	initEncoder (const SQLTypeInfo &tmp_sql_type)

void	syncEncoder (const AbstractBuffer *src_buffer)

void	copyTo (AbstractBuffer *destination_buffer, const size_t num_bytes=0)

void	resetToEmpty ()

Protected Attributes
int8_t *	mem_

Protected Attributes inherited from Data_Namespace::AbstractBuffer
std::unique_ptr< Encoder >	encoder_

SQLTypeInfo	sql_type_

size_t	size_

int	device_id_

Private Member Functions
	Buffer (const Buffer &)
	pointer to beginning of buffer's memory More...

Buffer &	operator= (const Buffer &)

virtual void	readData (int8_t *const dst, const size_t num_bytes, const size_t offset=0, const MemoryLevel dst_buffer_type=CPU_LEVEL, const int dst_device_id=-1)=0

virtual void	writeData (int8_t *const src, const size_t num_bytes, const size_t offset=0, const MemoryLevel src_buffer_type=CPU_LEVEL, const int src_device_id=-1)=0

Private Attributes
BufferMgr *	bm_

BufferList::iterator	seg_it_

size_t	page_size_

size_t	num_pages_
	the size of each page in the buffer More...

int	epoch_

std::vector< bool >	page_dirty_flags_
	indicates when the buffer was last flushed More...

int	pin_count_

std::mutex	pin_mutex_

Friends
class	BufferMgr

class	FileMgr

Detailed Description

Note(s): Forbid Copying Idiom 4.1.

Definition at line 42 of file Buffer.h.

Constructor & Destructor Documentation

Buffer_Namespace::Buffer::Buffer	(	BufferMgr *	bm,
		BufferList::iterator	seg_it,
		const int	device_id,
		const size_t	page_size = `512`,
		const size_t	num_bytes = `0`
	)

Constructs a Buffer object. The constructor requires a memory address (provided by BufferMgr), number of pages, and the size in bytes of each page. Additionally, the Buffer can be initialized with an epoch.

Parameters

mem	The beginning memory address of the buffer.
numPages	The number of pages into which the buffer's memory space is divided.
pageSize	The size in bytes of each page that composes the buffer.
epoch	A temporal reference implying the buffer is up-to-date up to the epoch.

Definition at line 27 of file Buffer.cpp.

References pin(), reserve(), and seg_it_.

     : AbstractBuffer(device_id)
     , mem_(nullptr)
     , bm_(bm)
     , seg_it_(seg_it)
     , page_size_(page_size)
     , num_pages_(0)
     , pin_count_(0) {
   pin();
   // so that the pointer value of this Buffer is stored
   seg_it_->buffer = this;
   if (num_bytes > 0) {
     reserve(num_bytes);
   }
 }

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Buffer_Namespace::Buffer::~Buffer ( )

override

Destructor.

Definition at line 47 of file Buffer.cpp.

47 {}

Buffer_Namespace::Buffer::Buffer ( const Buffer & )

private

pointer to beginning of buffer's memory

Member Function Documentation

void Buffer_Namespace::Buffer::append	(	int8_t *	src,
		const size_t	num_bytes,
		const MemoryLevel	src_buffer_type = `CPU_LEVEL`,
		const int	deviceId = `-1`
	)

overridevirtual

Implements Data_Namespace::AbstractBuffer.

Definition at line 120 of file Buffer.cpp.

References reserve(), reservedSize(), Data_Namespace::AbstractBuffer::setAppended(), Data_Namespace::AbstractBuffer::size_, and writeData().

                                              {
 #ifdef BUFFER_MUTEX
   boost::shared_lock<boost::shared_mutex> read_lock(
       read_write_mutex_);  // keep another thread from getting a write lock
   boost::unique_lock<boost::shared_mutex> append_lock(
       append_mutex_);  // keep another thread from getting an append lock
 #endif
 
   setAppended();
 
   if (num_bytes + size_ > reservedSize()) {
     reserve(num_bytes + size_);
   }
 
   writeData(src, num_bytes, size_, src_buffer_type, src_device_id);
   size_ += num_bytes;
   // Do we worry about dirty flags here or does append avoid them
 }

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int8_t * Buffer_Namespace::Buffer::getMemoryPtr ( )

overridevirtual

Returns a raw, constant (read-only) pointer to the underlying buffer.

Returns: A constant memory pointer for read-only access.

Implements Data_Namespace::AbstractBuffer.

Definition at line 142 of file Buffer.cpp.

References mem_.

                              {
   return mem_;
 }

int Buffer_Namespace::Buffer::getPinCount ( )

inlineoverridevirtual

Reimplemented from Data_Namespace::AbstractBuffer.

Definition at line 137 of file Buffer.h.

                                     {
     std::lock_guard<std::mutex> pin_lock(pin_mutex_);
     return (pin_count_);
   }

int32_t Buffer_Namespace::Buffer::getSlabNum ( ) const

inline

Definition at line 143 of file Buffer.h.

143 { return seg_it_->slab_num; }

Buffer_Namespace::Buffer::seg_it_

BufferList::iterator seg_it_

Definition: Buffer.h:163

Buffer& Buffer_Namespace::Buffer::operator= ( const Buffer & )

private

size_t Buffer_Namespace::Buffer::pageCount ( ) const

inlineoverridevirtual

Returns the number of pages in the buffer.

Implements Data_Namespace::AbstractBuffer.

Definition at line 121 of file Buffer.h.

121 { return num_pages_; }

Buffer_Namespace::Buffer::num_pages_

size_t num_pages_

the size of each page in the buffer

Definition: Buffer.h:165

size_t Buffer_Namespace::Buffer::pageSize ( ) const

inlineoverridevirtual

Returns the size in bytes of each page in the buffer.

Implements Data_Namespace::AbstractBuffer.

Definition at line 124 of file Buffer.h.

124 { return page_size_; }

Buffer_Namespace::Buffer::page_size_

size_t page_size_

Definition: Buffer.h:164

int Buffer_Namespace::Buffer::pin ( )

inlineoverridevirtual

Reimplemented from Data_Namespace::AbstractBuffer.

Definition at line 126 of file Buffer.h.

Referenced by Buffer().

                             {
     std::lock_guard<std::mutex> pin_lock(pin_mutex_);
     return (++pin_count_);
   }

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void Buffer_Namespace::Buffer::read	(	int8_t *const	dst,
		const size_t	num_bytes,
		const size_t	offset = `0`,
		const MemoryLevel	dst_buffer_type = `CPU_LEVEL`,
		const int	device_id = `-1`
	)

overridevirtual

Reads (copies) data from the buffer to the destination (dst) memory location. Reads (copies) nbytes of data from the buffer, beginning at the specified byte offset, into the destination (dst) memory location.

Parameters

dst	The destination address to where the buffer's data is being copied.
offset	The byte offset into the buffer from where reading (copying) begins.
nbytes	The number of bytes being read (copied) into the destination (dst).

Implements Data_Namespace::AbstractBuffer.

Definition at line 67 of file Buffer.cpp.

References CHECK, logger::FATAL, LOG, mem_, readData(), and Data_Namespace::AbstractBuffer::size_.

                                            {
   if (num_bytes == 0) {
     return;
   }
   CHECK(dst && mem_);
 #ifdef BUFFER_MUTEX
   boost::shared_lock<boost::shared_mutex> read_lock(read_write_mutex_);
 #endif
 
   if (num_bytes + offset > size_) {
     LOG(FATAL) << "Buffer: Out of bounds read error";
   }
   readData(dst, num_bytes, offset, dst_buffer_type, dst_device_id);
 }

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virtual void Buffer_Namespace::Buffer::readData	(	int8_t *const	dst,
		const size_t	num_bytes,
		const size_t	offset = `0`,
		const MemoryLevel	dst_buffer_type = `CPU_LEVEL`,
		const int	dst_device_id = `-1`
	)

privatepure virtual

Implemented in Buffer_Namespace::CpuBuffer, and Buffer_Namespace::GpuCudaBuffer.

Referenced by read().

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void Buffer_Namespace::Buffer::reserve ( const size_t num_bytes )

overridevirtual

Implements Data_Namespace::AbstractBuffer.

Definition at line 49 of file Buffer.cpp.

References bm_, num_pages_, page_dirty_flags_, page_size_, Buffer_Namespace::BufferMgr::reserveBuffer(), and seg_it_.

Referenced by append(), Buffer(), and write().

                                            {
 #ifdef BUFFER_MUTEX
   boost::unique_lock<boost::shared_mutex> write_lock(read_write_mutex_);
 #endif
   size_t num_pages = (num_bytes + page_size_ - 1) / page_size_;
   // std::cout << "NumPages reserved: " << numPages << std::endl;
   if (num_pages > num_pages_) {
     // When running out of cpu buffers, reserveBuffer() will fail and
     // trigger a SlabTooBig exception, so pageDirtyFlags_ and numPages_
     // MUST NOT be set until reserveBuffer() returns; otherwise, this
     // buffer is not properly resized, so any call to FileMgr::fetchBuffer()
     // will proceed to read(), corrupt heap memory and cause core dump later.
     seg_it_ = bm_->reserveBuffer(seg_it_, page_size_ * num_pages);
     page_dirty_flags_.resize(num_pages);
     num_pages_ = num_pages;
   }
 }

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size_t Buffer_Namespace::Buffer::reservedSize ( ) const

inlineoverridevirtual

Returns the total number of bytes allocated for the buffer.

Implements Data_Namespace::AbstractBuffer.

Definition at line 118 of file Buffer.h.

Referenced by append(), and write().

118 { return page_size_ * num_pages_; }

Buffer_Namespace::Buffer::num_pages_

size_t num_pages_

the size of each page in the buffer

Definition: Buffer.h:165

Buffer_Namespace::Buffer::page_size_

size_t page_size_

Definition: Buffer.h:164

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void Buffer_Namespace::Buffer::setMemoryPtr ( int8_t * new_ptr )

overridevirtual

Reimplemented from Data_Namespace::AbstractBuffer.

Definition at line 146 of file Buffer.cpp.

References mem_.

                                          {
   mem_ = new_ptr;
 }

int Buffer_Namespace::Buffer::unPin ( )

inlineoverridevirtual

Reimplemented from Data_Namespace::AbstractBuffer.

Definition at line 131 of file Buffer.h.

References CHECK.

                               {
     std::lock_guard<std::mutex> pin_lock(pin_mutex_);
     CHECK(pin_count_ > 0);
     return (--pin_count_);
   }

void Buffer_Namespace::Buffer::write	(	int8_t *	src,
		const size_t	num_bytes,
		const size_t	offset = `0`,
		const MemoryLevel	src_buffer_type = `CPU_LEVEL`,
		const int	device_id = `-1`
	)

overridevirtual

Writes (copies) data from src into the buffer. Writes (copies) nbytes of data into the buffer at the specified byte offset, from the source (src) memory location.

Parameters

src	The source address from where data is being copied to the buffer.
num_bytes	The number of bytes being written (copied) into the buffer.
offset	The byte offset into the buffer to where writing begins.

Implements Data_Namespace::AbstractBuffer.

Definition at line 86 of file Buffer.cpp.

References CHECK_GT, page_dirty_flags_, page_size_, reserve(), reservedSize(), Data_Namespace::AbstractBuffer::setAppended(), Data_Namespace::AbstractBuffer::setDirty(), Data_Namespace::AbstractBuffer::setUpdated(), Data_Namespace::AbstractBuffer::size_, and writeData().

                                             {
   CHECK_GT(num_bytes, size_t(0));  // cannot write 0 bytes
 #ifdef BUFFER_MUTEX
   boost::unique_lock<boost::shared_mutex> write_lock(read_write_mutex_);
 #endif
   if (num_bytes + offset > reservedSize()) {
     reserve(num_bytes + offset);
   }
   // write source contents to buffer
   writeData(src, num_bytes, offset, src_buffer_type, src_device_id);
 
   // update dirty flags for buffer and each affected page
   setDirty();
   if (offset < size_) {
     setUpdated();
   }
   if (offset + num_bytes > size_) {
     setAppended();
     size_ = offset + num_bytes;
   }
 
   // std::cout << "Size after write: " << size_ << std::endl;
 
   size_t first_dirty_page = offset / page_size_;
   size_t last_dirty_page = (offset + num_bytes - 1) / page_size_;
   for (size_t i = first_dirty_page; i <= last_dirty_page; ++i) {
     page_dirty_flags_[i] = true;
   }
 }

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virtual void Buffer_Namespace::Buffer::writeData	(	int8_t *const	src,
		const size_t	num_bytes,
		const size_t	offset = `0`,
		const MemoryLevel	src_buffer_type = `CPU_LEVEL`,
		const int	src_device_id = `-1`
	)

privatepure virtual

Implemented in Buffer_Namespace::CpuBuffer, and Buffer_Namespace::GpuCudaBuffer.

Referenced by append(), and write().

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Friends And Related Function Documentation

friend class BufferMgr

friend

Definition at line 43 of file Buffer.h.

friend class FileMgr

friend

Definition at line 44 of file Buffer.h.

Member Data Documentation

BufferMgr* Buffer_Namespace::Buffer::bm_

private

Definition at line 162 of file Buffer.h.

Referenced by reserve().

int Buffer_Namespace::Buffer::epoch_

private

Definition at line 166 of file Buffer.h.

int8_t* Buffer_Namespace::Buffer::mem_

protected

Definition at line 146 of file Buffer.h.

Referenced by getMemoryPtr(), read(), Buffer_Namespace::GpuCudaBuffer::readData(), Buffer_Namespace::CpuBuffer::readData(), setMemoryPtr(), Buffer_Namespace::GpuCudaBuffer::writeData(), and Buffer_Namespace::CpuBuffer::writeData().

size_t Buffer_Namespace::Buffer::num_pages_

private

the size of each page in the buffer

Definition at line 165 of file Buffer.h.

Referenced by reserve().

std::vector<bool> Buffer_Namespace::Buffer::page_dirty_flags_

private

indicates when the buffer was last flushed

Definition at line 167 of file Buffer.h.

Referenced by reserve(), and write().

size_t Buffer_Namespace::Buffer::page_size_

private

Definition at line 164 of file Buffer.h.

Referenced by reserve(), and write().

int Buffer_Namespace::Buffer::pin_count_

private

Definition at line 168 of file Buffer.h.

std::mutex Buffer_Namespace::Buffer::pin_mutex_

private

Definition at line 169 of file Buffer.h.

BufferList::iterator Buffer_Namespace::Buffer::seg_it_

private

Definition at line 163 of file Buffer.h.

Referenced by Buffer(), Buffer_Namespace::BufferMgr::free(), and reserve().

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

/home/jenkins-slave/workspace/core-os-doxygen/DataMgr/BufferMgr/Buffer.h
/home/jenkins-slave/workspace/core-os-doxygen/DataMgr/BufferMgr/Buffer.cpp

Public Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation