Buffering apparatus and buffering method using ring buffer
View Patent ↗A read unit in a buffering apparatus writes data in a memory apparatus used as a ring buffer. A determination unit determines whether data is consecutively written in the memory apparatus. When it in determined that data in consecutively written, the determination unit, in response to a request for transfer of data from a central processing unit, directs the read unit to read ahead data that follows the data requested to be transferred. In response to a request to read ahead, the read unit reads ahead the data from a recording medium and writes the data thus read ahead in the memory apparatus. In response to the instruction to read ahead, the read unit reads ahead a predetermined amount of data that follows the data requested to be transferred.
1. A buffering apparatus comprising:
a memory apparatus provided with a plurality of storage areas assigned consecutive identification numbers;
a read unit which reads data recorded in a recording medium and writes the data in the memory apparatus; and
a determination unit which determines whether the data beginning with the data requested to be transferred from the memory apparatus and ending with the most recently written data is located in the order of sector numbers in a contiguous range of storage areas, and decides whether to direct the read unit to read ahead from the recording medium according to the determination.
2. The buffering apparatus according to claim 1 , wherein the read unit uses the memory apparatus as a ring buffer to write the data.
3. The buffering apparatus according to claim 1 , wherein, in response to a request for transfer of data, the determination unit directs the read unit to read ahead data that follows the data requested to be transferred, and, in response to a read ahead instruction, the read unit reads ahead the following data from the recording medium and writes the data thus read ahead in the memory apparatus.
4. The buffering apparatus according to claim 3 , wherein, in response to the read ahead instruction, the read unit reads ahead a predetermined amount of data that follows the data requested to be transferred.
5. The buffering apparatus according to claim 3 , wherein the determination unit directs the read unit to read ahead if the data beginning with the data requested to be transferred and ending with the most recently written data is located in the order of sector numbers in a contiguous range of storage areas beginning with the storage area in which the data requested to be transferred is written and ending with the storage area in which the most recent data is written.
6. The buffering apparatus according to claim 3 , wherein the determination unit does not direct the read unit to read ahead if the data beginning with the data requested to be transferred and ending with the most recently written data is not located in the order of sector numbers in a contiguous range of storage areas beginning with the storage area in which the data requested to be transferred is written and ending with the storage area in which the most recent data is written.
7. The buffering apparatus according to claim 1 , wherein
the sector numbers relate to units of data stored on the recording medium, and
the determination unit retains a management table which indicates a correspondence between the identification numbers and the sector numbers.
8. The buffering method according to claim 1 , wherein the memory apparatus is partitioned into a locked area and an unlocked area, the unlocked area including the plurality of storage areas assigned consecutive identification numbers.
9. The buffering method according to claim 8 , wherein:
the locked area includes data for operating a processor; and
the unlocked area includes data cached from a disk and operates as a ring buffer.
10. The buffering method according to claim 8 , further comprising designating a partition between the locked area and the unlocked area dynamically during operation.
11. The buffering method according to claim 1 , wherein the locked area does not include any of the plurality of storage areas assigned consecutive identification numbers.
12. A buffering method for a memory apparatus provided with a plurality of storage areas assigned consecutive identification numbers, comprising:
reading data recorded in a recording medium and writing the data in the memory apparatus; and
determining whether the data beginning with the data requested to be transferred from the memory apparatus and ending with the most recently written data is located in the order of sector numbers in a contiguous range of storage areas; and
deciding whether to direct the read unit to read ahead from the recording medium according to the determination.
13. The buffering method according to claim 12 , further comprising:
referring to a management table which indicates a correspondence between the identification numbers and the sector numbers, in which the sector numbers relate to units of data stored on the recording medium.