Method and device for circularly reading and writing in buffer zone

Abstract

The invention discloses a method for circularly reading and writing in a buffer zone, which comprises the following steps: when to-be-written data is written into the buffer zone but the tail space of the buffer zone is insufficient to store the complete to-be-written data, writing the to-be-written data from a starting position of the buffer zone and marking on the tail of data in the buffer zone; and when the data is read from the buffer zone and an address-reading pointer points at the mark, directly searching for the valid data position from the starting position of the buffer zone and then performing the subsequent data-reading operation. The invention also discloses a device for circularly reading and writing in the buffer zone. By using the method and device, the speed for reading data can be increased while the operation for reading data is simple and convenient.

Description

technical field [0001] The invention relates to the field of storage technology, in particular to a method and device for circularly reading and writing a buffer. Background technique [0002] At present, when using the buffer for data reading and writing, a certain method is generally used to realize the circular reading and writing of the buffer. Specific steps are as follows: [0003] First allocate a fixed-size memory for the program, for example, use pBufferBeginPtr to mark the starting address of the block of memory, and then define two pointer objects m_pReadPtr and pWritePtr; m_pReadPtr is used to mark the position of the buffer read data, m_pWritePtr is used to mark and buffer The location where the area is written. [0004] When writing data, first combine the data into the format of delimiter + data length + data, for example, mark the combined data with pData (the data length of pData is nDataLen), and then judge whether the remaining space of the buffer can st...

AI Technical Summary

Problems solved by technology

[0009] If writing mode 1 is used, then when calculating aDataLen, it is necessary to first determine how the data is stored. If a part of the data is stored at the end of the buffer and a part of the bytes is stored at the beginning of the buffer, then when calculating aDataLen, it is necessary to first Combine these two parts of bytes, and then calculate the length based on the combined bytes. This method is cumbersome and not easy enough when calculating aDataLen

[0010] If writing method 2 is used, when the end of the buffer is read, because there are some invalid data, when searching for valid data, the entire invalid data at the end must be searched, and then the search will start from the beginning of the buffer, and this process will waste Part of the search time, reducing the speed of data reading

Images