Class DataBlockRead

• Defined in File DataBlockRead.h

Inheritance Relationships

Base Type

• public ska::pst::smrb::DataBlockAccessor (Class DataBlockAccessor)

Class Documentation

class DataBlockRead : public ska::pst::smrb::DataBlockAccessor

Object Oriented interface to read to a PSRDADA Shared Memory Ring Buffer (SMRB).

Public Functions

explicit DataBlockRead(const std::string &key)

Construct a new Data Block Read object for the SMRB identified by the key.

Parameters

key – 4 character hexidecimal key that identifies the SMRB in shared memory.

~DataBlockRead()

Destroy the Data Block Read object. Closes the access to the SMRB if required.

virtual void open() override

Open the SMRB for reading.

virtual void lock() override

Lock read access to the SMRB.

virtual void close() override

Close the connection to the SMRB.

virtual void unlock() override

Unlock read access to the SMRB.

void read_config()

Read the scan configuration from the header_block.

void read_header()

Read the complete header from the header_block.

ssize_t read_data(char *buffer, size_t nbytes)

Read requested nbytes from the datablock into the provided buffer.

Parameters

• buffer –

• nbytes –

Returns

ssize_t

virtual char *open_block() override

Open a data_block buffer for DMA.

Returns

void* pointer to the opened data_block buffer

virtual ssize_t close_block(uint64_t bytes) override

Close an opened data_block buffer specifying the number of bytes read.

Parameters

bytes – number of bytes read to the opened data_block buffer

Returns

ssize_t number of bytes read

ssize_t update_block(uint64_t bytes)

Update the number of bytes read to the opened data_block buffer.

Parameters

bytes – number of bytes read

Returns

ssize_t number of bytes read

void zero_next_block()

zero the buffer in the data_block after the currently opened buffer

bool check_eod()

Check if the End-Of-Data flag on the data block.

Returns

true if the End-Of-Data flag has been raised