[HDFS-8376] Erasure Coding: Update last cellsize calculation according to whether the erasure codec has chunk boundary

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Invalid
• Assignee: Yi Liu
• Reporter: Yi Liu
• Created: 12/May/15 07:23
• Updated: 16/Oct/15 08:07
• Resolved: 16/Oct/15 08:07

Description

Current calculation for last cell size is as following. For parity cell, the last cell size is the same as the first data cell. But some erasure codec has chunk boundary, then the last cellsize for parity block is the codec chunk size.

private static int lastCellSize(int size, int cellSize, int numDataBlocks,
      int i) {
    if (i < numDataBlocks) {
      // parity block size (i.e. i >= numDataBlocks) is the same as 
      // the first data block size (i.e. i = 0).
      size -= i*cellSize;
      if (size < 0) {
        size = 0;
      }
    }
    return size > cellSize? cellSize: size;
  }