dfmbuf_copy: Copy a z/TPFDF multiple LREC buffer

Last updated

Added for PUT11.

Entry requirements

• The z/TPFDF multiple LREC buffers that the buf_ptr and target_ptr parameters reference must both be allocated and previously initialized by using the dfmbuf_init or dfmbuf_init_v2 function.
• The z/TPFDF multiple LREC buffer that the target_ptr parameter references must not be a local copy of the buffer header and must not be previously published.

Return conditions

None.

Error return

For information about how to check the error indicators, see Identifying return indicators and errors.

Programming considerations

• You can copy data between different header versions of a z/TPFDF multiple LREC buffer.
• If the source buffer or the target buffer was initialized with header version 1, the dfmbuf_copy function ignores any active keys for both source and target buffers and appends all data from the source buffer at the end of the target buffer.
• If both the source and target buffers were initialized with header version 2, keys can be used as the following conditions:
  • If active keys exist in the source buffer and the DFMBUF_NOKEY value is not specified, the keys are used as a selection criteria for the data that needs to be copied.
  • If active keys exist in the target buffer and the DFMBUF_NOTARGETKEY value is not specified, the keys are used as organization keys to determine where data gets added into the target buffer.
• If space in the target buffer is not enough for all LRECs, the following actions occur:
  • The current LREC in the source buffer is set to the first LREC that was not copied.
  • The return value is set to DF_MBUF_NO_SPACE.
  To copy the rest of the LRECs, you can take the following actions:

  1. Allocate a larger size for the target buffer.
  2. Call the dfmbuf_resize function for the target buffer.
  3. Repeat the dfmbuf_copy function without the DFMBUF_BEGIN value specified to continue to copy the remaining LRECs.