flamenco: add instrs reset to txn generation

firedancer-io · May 16, 2024 · ee2e75e · ee2e75e
1 parent a1c97a7
commit ee2e75e
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Showing 2 changed files with 33 additions and 8 deletions.
diff --git a/src/flamenco/txn/fd_txn_generate.c b/src/flamenco/txn/fd_txn_generate.c
@@ -32,8 +32,10 @@ fd_txn_base_generate( uchar out_txn_meta[ static FD_TXN_MAX_SZ ],
                       fd_txn_accounts_t * accounts,
                       uchar * opt_recent_blockhash ) {
 
-  FD_TEST(num_signatures <= 128);
+  /* Number of signatures cannot exceed 127. */
+  FD_TEST(num_signatures <= FD_TXN_SIG_MAX);
   *out_txn_payload = (uchar)num_signatures;
+
   /* Fill out txn metadata */
   fd_txn_t * txn_meta             = (fd_txn_t *) out_txn_meta;
   txn_meta->acct_addr_cnt         = accounts->acct_cnt;
@@ -105,13 +107,13 @@ fd_txn_add_instr( uchar * txn_meta_ptr,
   txn_meta->instr_cnt++;
   uchar * write_ptr       = instr_start;
 
-  uchar compact_instr_cnt_sz = (uchar) fd_cu16_enc( (ushort)txn_meta->instr_cnt, write_ptr );
+  uint compact_instr_cnt_sz = fd_cu16_enc( (ushort)txn_meta->instr_cnt, write_ptr );
   FD_TEST( compact_instr_cnt_sz == 1 );
 
   write_ptr += compact_instr_cnt_sz;
 
   /* Calculate offset of next instruction. */
-  if ( txn_meta->instr_cnt > 1 ) {
+  if ( FD_UNLIKELY( txn_meta->instr_cnt > 1 ) ) {
     write_ptr = out_txn_payload + txn_meta->instr[txn_meta->instr_cnt-2].data_off + txn_meta->instr[txn_meta->instr_cnt-2].data_sz;
   }
 
@@ -120,9 +122,10 @@ fd_txn_add_instr( uchar * txn_meta_ptr,
   *write_ptr = program_id;
   write_ptr += sizeof(uchar);
 
-  uchar compact_accts_len_sz = (uchar) fd_cu16_enc( (ushort)accounts_sz, write_ptr );
+  uint compact_accts_len_sz = fd_cu16_enc( (ushort)accounts_sz, write_ptr );
   write_ptr += compact_accts_len_sz;
 
+  ushort acct_off = (ushort) (write_ptr - out_txn_payload);
   fd_memcpy( write_ptr, accounts, accounts_sz );
   write_ptr += accounts_sz;
 
@@ -134,11 +137,24 @@ fd_txn_add_instr( uchar * txn_meta_ptr,
   ushort data_off = (ushort) (write_ptr - out_txn_payload);
   fd_memcpy( write_ptr, instr_buf, data_sz );
   write_ptr += data_sz;
-  ushort acct_off = (ushort) (instr_start + sizeof(uchar) + compact_accts_len_sz - out_txn_payload);
 
   (void) fd_txn_instr_meta_generate( (uchar*)&txn_meta->instr[txn_meta->instr_cnt-1], 
                                       program_id, 
                                       (ushort)accounts_sz,
                                       data_sz, acct_off, data_off );
-  return (ulong)(write_ptr - out_txn_payload);
+  return (ulong)(instr_start - 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;
+  if( FD_UNLIKELY( txn_meta->instr_cnt == 0 ) ) {
+    return;
+  }
+
+  ulong instr_start   = txn_meta->recent_blockhash_off + FD_TXN_BLOCKHASH_SZ;
+
+  *(out_txn_payload + instr_start) = 0;
+  txn_meta->instr_cnt = 0;
 }
diff --git a/src/flamenco/txn/fd_txn_generate.h b/src/flamenco/txn/fd_txn_generate.h
@@ -26,7 +26,9 @@ typedef struct fd_txn_accounts fd_txn_accounts_t;
 
 FD_PROTOTYPES_BEGIN
 
-/* Method used to create a template for a txn (useful for pre-staging and re-use) */
+/* Method used to create a template for a txn (useful for pre-staging and re-use)
+   Num signatures is restricted to < 128. Returns the offset to the start of the
+   insructions. */
 ulong
 fd_txn_base_generate( uchar out_txn_meta[ static FD_TXN_MAX_SZ ],
                       uchar out_txn_payload[ static FD_TXN_MTU ],
@@ -37,7 +39,8 @@ fd_txn_base_generate( uchar out_txn_meta[ static FD_TXN_MAX_SZ ],
 /* Method used for adding an instruction to a txn being generated.
    The accounts param is a list of indices to the accounts in the txn.
    The instruction buffer contains the data for the instruction to
-   be added. */
+   be added. Returns the offset to the start of the instruction added
+   in the transaction buffer. */
 ulong
 fd_txn_add_instr( uchar * txn_meta_ptr,
                   uchar out_txn_payload[ static FD_TXN_MTU ],
@@ -46,4 +49,10 @@ 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