Initial project import

tools/v/thirdparty/libgc/include/gc/ec.h

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 1993-1994 by Xerox Corporation.  All rights reserved.
+ *
+ * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+ * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
+ *
+ * Permission is hereby granted to use or copy this program
+ * for any purpose, provided the above notices are retained on all copies.
+ * Permission to modify the code and to distribute modified code is granted,
+ * provided the above notices are retained, and a notice that the code was
+ * modified is included with the above copyright notice.
+ */
+
+#ifndef EC_H
+#define EC_H
+
+#ifndef CORD_H
+#  include "cord.h"
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Extensible cords are strings that may be destructively appended to.
+ * They allow fast construction of cords from characters that are being
+ * read from a stream.
+ *
+ * A client might look like:
+ * ```
+ *   CORD_ec x;
+ *   CORD result;
+ *   char c;
+ *   FILE *f;
+ *
+ *   CORD_ec_init(x);
+ *   while (...) {
+ *       c = getc(f);
+ *       ...
+ *       CORD_ec_append(x, c);
+ *   }
+ *   result = CORD_balance(CORD_ec_to_cord(x));
+ * ```
+ *
+ * If a C string is desired as the final result, the call to `CORD_balance`
+ * may be replaced by a call to `CORD_to_char_star`.
+ */
+
+#ifndef CORD_BUFSZ
+#  define CORD_BUFSZ 128
+#endif
+
+/**
+ * This structure represents the concatenation of `ec_cord` with
+ * `ec_buf[0 .. ec_bufptr - ec_buf - 1]`.
+ */
+typedef struct CORD_ec_struct {
+  CORD ec_cord;
+  char *ec_bufptr;
+  char ec_buf[CORD_BUFSZ + 1];
+} CORD_ec[1];
+
+/** Flush the buffer part of the extended cord into extensible cord. */
+CORD_API void CORD_ec_flush_buf(CORD_ec);
+
+/** Convert an extensible cord to a cord. */
+#define CORD_ec_to_cord(x) (CORD_ec_flush_buf(x), (x)[0].ec_cord)
+
+/** Initialize an extensible cord. */
+#define CORD_ec_init(x) \
+  ((x)[0].ec_cord = 0, (void)((x)[0].ec_bufptr = (x)[0].ec_buf))
+
+/** Append a character to an extensible cord. */
+#define CORD_ec_append(x, c)                             \
+  ((void)((x)[0].ec_bufptr == (x)[0].ec_buf + CORD_BUFSZ \
+              ? (CORD_ec_flush_buf(x), 0)                \
+              : 0),                                      \
+   (void)(*(x)[0].ec_bufptr++ = (c)))
+
+/**
+ * Append a cord to an extensible cord.  Structure remains shared with
+ * the original.
+ */
+CORD_API void CORD_ec_append_cord(CORD_ec, CORD);
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif /* EC_H */