flamenco: add instrs reset to txn generation

firedancer-io · May 15, 2024 · ef53516 · ef53516
1 parent a9c25fe
commit ef53516
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Showing 2 changed files with 20 additions and 0 deletions.
diff --git a/src/flamenco/txn/fd_txn_generate.c b/src/flamenco/txn/fd_txn_generate.c
@@ -142,3 +142,17 @@ fd_txn_add_instr( uchar * txn_meta_ptr,
                                       data_sz, acct_off, data_off );
   return (ulong)(write_ptr - out_txn_payload);
 }
+
+void
+fd_txn_reset_instrs( uchar * txn_meta_ptr,
+                     uchar out_txn_payload[ static FD_TXN_MTU ] ) {
+  fd_txn_t * txn_meta = (fd_txn_t *)txn_meta_ptr;
+  ulong instr_start   = txn_meta->recent_blockhash_off + FD_TXN_BLOCKHASH_SZ;
+
+  ushort num_instrs   = txn_meta->instr_cnt;
+  ulong instrs_sz     = txn_meta->instr[num_instrs-1].data_off + txn_meta->instr[num_instrs-1].data_sz - instr_start;
+
+  fd_memset( (out_txn_payload + instr_start), 0UL, instrs_sz );
+  fd_memset( txn_meta->instr, 0UL, num_instrs * sizeof(fd_txn_instr_t) );
+  txn_meta->instr_cnt = 0;
+}
diff --git a/src/flamenco/txn/fd_txn_generate.h b/src/flamenco/txn/fd_txn_generate.h
@@ -46,4 +46,10 @@ fd_txn_add_instr( uchar * txn_meta_ptr,
                   ulong accounts_sz,
                   uchar const * instr_buf,
                   ulong instr_buf_sz );
+
+/* Helper method to reset the list of instrs in the metadata and
+   remove all instrs from the txn payload. */
+void
+fd_txn_reset_instrs( uchar * txn_meta_ptr,
+                     uchar out_txn_payload[ static FD_TXN_MTU ] );
 FD_PROTOTYPES_END