1 files changed, 75 insertions, 0 deletions
diff --git a/llparse/src/implementation/c/helpers/match-sequence.ts b/llparse/src/implementation/c/helpers/match-sequence.ts
new file mode 100644
index 0000000..278f4b5
--- /dev/null
+++ b/llparse/src/implementation/c/helpers/match-sequence.ts
@@ -0,0 +1,75 @@
+import * as assert from 'assert';
+import { Buffer } from 'buffer';
+import * as frontend from 'llparse-frontend';
+
+import {
+  SEQUENCE_COMPLETE, SEQUENCE_MISMATCH, SEQUENCE_PAUSE,
+} from '../constants';
+import { Transform } from '../transform';
+import { Compilation } from '../compilation';
+
+type TransformWrap = Transform<frontend.transform.Transform>;
+
+export class MatchSequence {
+  constructor(private readonly transform: TransformWrap) {
+  }
+
+  public static buildGlobals(out: string[]): void {
+    out.push('enum llparse_match_status_e {');
+    out.push(`  ${SEQUENCE_COMPLETE},`);
+    out.push(`  ${SEQUENCE_PAUSE},`);
+    out.push(`  ${SEQUENCE_MISMATCH}`);
+    out.push('};');
+    out.push('typedef enum llparse_match_status_e llparse_match_status_t;');
+    out.push('');
+    out.push('struct llparse_match_s {');
+    out.push('  llparse_match_status_t status;');
+    out.push('  const unsigned char* current;');
+    out.push('};');
+    out.push('typedef struct llparse_match_s llparse_match_t;');
+  }
+
+  public getName(): string {
+    return `llparse__match_sequence_${this.transform.ref.name}`;
+  }
+
+  public build(ctx: Compilation, out: string[]): void {
+    out.push(`static llparse_match_t ${this.getName()}(`);
+    out.push(`    ${ctx.prefix}_t* s, const unsigned char* p,`);
+    out.push('    const unsigned char* endp,');
+    out.push('    const unsigned char* seq, uint32_t seq_len) {');
+
+    // Vars
+    out.push('  uint32_t index;');
+    out.push('  llparse_match_t res;');
+    out.push('');
+
+    // Body
+    out.push('  index = s->_index;');
+    out.push('  for (; p != endp; p++) {');
+    out.push('    unsigned char current;');
+    out.push('');
+    out.push(`    current = ${this.transform.build(ctx, '*p')};`);
+    out.push('    if (current == seq[index]) {');
+    out.push('      if (++index == seq_len) {');
+    out.push(`        res.status = ${SEQUENCE_COMPLETE};`);
+    out.push('        goto reset;');
+    out.push('      }');
+    out.push('    } else {');
+    out.push(`      res.status = ${SEQUENCE_MISMATCH};`);
+    out.push('      goto reset;');
+    out.push('    }');
+    out.push('  }');
+
+    out.push('  s->_index = index;');
+    out.push(`  res.status = ${SEQUENCE_PAUSE};`);
+    out.push('  res.current = p;');
+    out.push('  return res;');
+
+    out.push('reset:');
+    out.push('  s->_index = 0;');
+    out.push('  res.current = p;');
+    out.push('  return res;');
+    out.push('}');
+  }
+}