Initial revision
This commit is contained in:
Akinori Ito
915
gc/cord/cordbscs.c
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915
gc/cord/cordbscs.c
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@@ -0,0 +1,915 @@
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/*
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* Copyright (c) 1993-1994 by Xerox Corporation. All rights reserved.
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*
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* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
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* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
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*
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* Permission is hereby granted to use or copy this program
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* for any purpose, provided the above notices are retained on all copies.
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* Permission to modify the code and to distribute modified code is granted,
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* provided the above notices are retained, and a notice that the code was
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* modified is included with the above copyright notice.
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*
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* Author: Hans-J. Boehm (boehm@parc.xerox.com)
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*/
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/* Boehm, October 3, 1994 5:19 pm PDT */
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# include "gc.h"
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# include "cord.h"
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# include <stdlib.h>
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# include <stdio.h>
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# include <string.h>
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/* An implementation of the cord primitives. These are the only */
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/* Functions that understand the representation. We perform only */
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/* minimal checks on arguments to these functions. Out of bounds */
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/* arguments to the iteration functions may result in client functions */
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/* invoked on garbage data. In most cases, client functions should be */
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/* programmed defensively enough that this does not result in memory */
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/* smashes. */
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typedef void (* oom_fn)(void);
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oom_fn CORD_oom_fn = (oom_fn) 0;
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# define OUT_OF_MEMORY { if (CORD_oom_fn != (oom_fn) 0) (*CORD_oom_fn)(); \
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ABORT("Out of memory\n"); }
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# define ABORT(msg) { fprintf(stderr, "%s\n", msg); abort(); }
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typedef unsigned long word;
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typedef union {
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struct Concatenation {
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char null;
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char header;
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char depth; /* concatenation nesting depth. */
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unsigned char left_len;
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/* Length of left child if it is sufficiently */
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/* short; 0 otherwise. */
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# define MAX_LEFT_LEN 255
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word len;
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CORD left; /* length(left) > 0 */
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CORD right; /* length(right) > 0 */
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} concatenation;
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struct Function {
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char null;
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char header;
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char depth; /* always 0 */
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char left_len; /* always 0 */
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word len;
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CORD_fn fn;
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void * client_data;
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} function;
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struct Generic {
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char null;
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char header;
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char depth;
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char left_len;
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word len;
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} generic;
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char string[1];
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} CordRep;
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# define CONCAT_HDR 1
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# define FN_HDR 4
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# define SUBSTR_HDR 6
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/* Substring nodes are a special case of function nodes. */
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/* The client_data field is known to point to a substr_args */
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/* structure, and the function is either CORD_apply_access_fn */
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/* or CORD_index_access_fn. */
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/* The following may be applied only to function and concatenation nodes: */
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#define IS_CONCATENATION(s) (((CordRep *)s)->generic.header == CONCAT_HDR)
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#define IS_FUNCTION(s) ((((CordRep *)s)->generic.header & FN_HDR) != 0)
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#define IS_SUBSTR(s) (((CordRep *)s)->generic.header == SUBSTR_HDR)
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#define LEN(s) (((CordRep *)s) -> generic.len)
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#define DEPTH(s) (((CordRep *)s) -> generic.depth)
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#define GEN_LEN(s) (CORD_IS_STRING(s) ? strlen(s) : LEN(s))
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#define LEFT_LEN(c) ((c) -> left_len != 0? \
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(c) -> left_len \
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: (CORD_IS_STRING((c) -> left) ? \
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(c) -> len - GEN_LEN((c) -> right) \
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: LEN((c) -> left)))
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#define SHORT_LIMIT (sizeof(CordRep) - 1)
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/* Cords shorter than this are C strings */
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/* Dump the internal representation of x to stdout, with initial */
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/* indentation level n. */
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void CORD_dump_inner(CORD x, unsigned n)
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{
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register size_t i;
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for (i = 0; i < (size_t)n; i++) {
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fputs(" ", stdout);
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}
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if (x == 0) {
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fputs("NIL\n", stdout);
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} else if (CORD_IS_STRING(x)) {
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for (i = 0; i <= SHORT_LIMIT; i++) {
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if (x[i] == '\0') break;
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putchar(x[i]);
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}
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if (x[i] != '\0') fputs("...", stdout);
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putchar('\n');
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} else if (IS_CONCATENATION(x)) {
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register struct Concatenation * conc =
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&(((CordRep *)x) -> concatenation);
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printf("Concatenation: %p (len: %d, depth: %d)\n",
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x, (int)(conc -> len), (int)(conc -> depth));
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CORD_dump_inner(conc -> left, n+1);
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CORD_dump_inner(conc -> right, n+1);
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} else /* function */{
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register struct Function * func =
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&(((CordRep *)x) -> function);
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if (IS_SUBSTR(x)) printf("(Substring) ");
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printf("Function: %p (len: %d): ", x, (int)(func -> len));
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for (i = 0; i < 20 && i < func -> len; i++) {
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putchar((*(func -> fn))(i, func -> client_data));
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}
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if (i < func -> len) fputs("...", stdout);
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putchar('\n');
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}
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}
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/* Dump the internal representation of x to stdout */
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void CORD_dump(CORD x)
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{
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CORD_dump_inner(x, 0);
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fflush(stdout);
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}
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CORD CORD_cat_char_star(CORD x, const char * y, size_t leny)
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{
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register size_t result_len;
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register size_t lenx;
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register int depth;
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if (x == CORD_EMPTY) return(y);
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if (leny == 0) return(x);
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if (CORD_IS_STRING(x)) {
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lenx = strlen(x);
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result_len = lenx + leny;
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if (result_len <= SHORT_LIMIT) {
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register char * result = GC_MALLOC_ATOMIC(result_len+1);
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if (result == 0) OUT_OF_MEMORY;
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memcpy(result, x, lenx);
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memcpy(result + lenx, y, leny);
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result[result_len] = '\0';
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return((CORD) result);
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} else {
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depth = 1;
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}
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} else {
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register CORD right;
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register CORD left;
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register char * new_right;
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register size_t right_len;
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lenx = LEN(x);
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if (leny <= SHORT_LIMIT/2
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&& IS_CONCATENATION(x)
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&& CORD_IS_STRING(right = ((CordRep *)x) -> concatenation.right)) {
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/* Merge y into right part of x. */
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if (!CORD_IS_STRING(left = ((CordRep *)x) -> concatenation.left)) {
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right_len = lenx - LEN(left);
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} else if (((CordRep *)x) -> concatenation.left_len != 0) {
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right_len = lenx - ((CordRep *)x) -> concatenation.left_len;
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} else {
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right_len = strlen(right);
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}
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result_len = right_len + leny; /* length of new_right */
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if (result_len <= SHORT_LIMIT) {
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new_right = GC_MALLOC_ATOMIC(result_len + 1);
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memcpy(new_right, right, right_len);
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memcpy(new_right + right_len, y, leny);
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new_right[result_len] = '\0';
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y = new_right;
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leny = result_len;
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x = left;
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lenx -= right_len;
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/* Now fall through to concatenate the two pieces: */
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}
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if (CORD_IS_STRING(x)) {
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depth = 1;
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} else {
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depth = DEPTH(x) + 1;
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}
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} else {
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depth = DEPTH(x) + 1;
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}
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result_len = lenx + leny;
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}
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{
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/* The general case; lenx, result_len is known: */
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register struct Concatenation * result;
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result = GC_NEW(struct Concatenation);
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if (result == 0) OUT_OF_MEMORY;
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result->header = CONCAT_HDR;
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result->depth = depth;
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if (lenx <= MAX_LEFT_LEN) result->left_len = lenx;
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result->len = result_len;
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result->left = x;
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result->right = y;
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if (depth > MAX_DEPTH) {
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return(CORD_balance((CORD)result));
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} else {
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return((CORD) result);
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}
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}
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}
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CORD CORD_cat(CORD x, CORD y)
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{
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register size_t result_len;
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register int depth;
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register size_t lenx;
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if (x == CORD_EMPTY) return(y);
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if (y == CORD_EMPTY) return(x);
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if (CORD_IS_STRING(y)) {
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return(CORD_cat_char_star(x, y, strlen(y)));
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} else if (CORD_IS_STRING(x)) {
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lenx = strlen(x);
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depth = DEPTH(y) + 1;
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} else {
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register int depthy = DEPTH(y);
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lenx = LEN(x);
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depth = DEPTH(x) + 1;
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if (depthy >= depth) depth = depthy + 1;
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}
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result_len = lenx + LEN(y);
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{
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register struct Concatenation * result;
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result = GC_NEW(struct Concatenation);
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if (result == 0) OUT_OF_MEMORY;
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result->header = CONCAT_HDR;
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result->depth = depth;
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if (lenx <= MAX_LEFT_LEN) result->left_len = lenx;
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result->len = result_len;
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result->left = x;
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result->right = y;
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return((CORD) result);
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}
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}
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CORD CORD_from_fn(CORD_fn fn, void * client_data, size_t len)
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{
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if (len <= 0) return(0);
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if (len <= SHORT_LIMIT) {
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register char * result;
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register size_t i;
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char buf[SHORT_LIMIT+1];
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register char c;
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for (i = 0; i < len; i++) {
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c = (*fn)(i, client_data);
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if (c == '\0') goto gen_case;
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buf[i] = c;
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}
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buf[i] = '\0';
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result = GC_MALLOC_ATOMIC(len+1);
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if (result == 0) OUT_OF_MEMORY;
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strcpy(result, buf);
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result[len] = '\0';
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return((CORD) result);
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}
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gen_case:
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{
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register struct Function * result;
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result = GC_NEW(struct Function);
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if (result == 0) OUT_OF_MEMORY;
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result->header = FN_HDR;
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/* depth is already 0 */
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result->len = len;
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result->fn = fn;
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result->client_data = client_data;
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return((CORD) result);
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}
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}
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size_t CORD_len(CORD x)
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{
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if (x == 0) {
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return(0);
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} else {
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return(GEN_LEN(x));
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}
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}
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struct substr_args {
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CordRep * sa_cord;
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size_t sa_index;
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};
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char CORD_index_access_fn(size_t i, void * client_data)
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{
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register struct substr_args *descr = (struct substr_args *)client_data;
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return(((char *)(descr->sa_cord))[i + descr->sa_index]);
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}
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char CORD_apply_access_fn(size_t i, void * client_data)
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{
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register struct substr_args *descr = (struct substr_args *)client_data;
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register struct Function * fn_cord = &(descr->sa_cord->function);
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return((*(fn_cord->fn))(i + descr->sa_index, fn_cord->client_data));
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}
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/* A version of CORD_substr that simply returns a function node, thus */
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/* postponing its work. The fourth argument is a function that may */
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/* be used for efficient access to the ith character. */
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/* Assumes i >= 0 and i + n < length(x). */
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CORD CORD_substr_closure(CORD x, size_t i, size_t n, CORD_fn f)
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{
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register struct substr_args * sa = GC_NEW(struct substr_args);
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CORD result;
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if (sa == 0) OUT_OF_MEMORY;
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sa->sa_cord = (CordRep *)x;
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sa->sa_index = i;
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result = CORD_from_fn(f, (void *)sa, n);
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((CordRep *)result) -> function.header = SUBSTR_HDR;
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return (result);
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}
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# define SUBSTR_LIMIT (10 * SHORT_LIMIT)
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/* Substrings of function nodes and flat strings shorter than */
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/* this are flat strings. Othewise we use a functional */
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/* representation, which is significantly slower to access. */
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/* A version of CORD_substr that assumes i >= 0, n > 0, and i + n < length(x).*/
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CORD CORD_substr_checked(CORD x, size_t i, size_t n)
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{
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if (CORD_IS_STRING(x)) {
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if (n > SUBSTR_LIMIT) {
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return(CORD_substr_closure(x, i, n, CORD_index_access_fn));
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} else {
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register char * result = GC_MALLOC_ATOMIC(n+1);
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if (result == 0) OUT_OF_MEMORY;
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strncpy(result, x+i, n);
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result[n] = '\0';
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return(result);
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}
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} else if (IS_CONCATENATION(x)) {
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register struct Concatenation * conc
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= &(((CordRep *)x) -> concatenation);
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register size_t left_len;
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register size_t right_len;
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left_len = LEFT_LEN(conc);
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right_len = conc -> len - left_len;
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if (i >= left_len) {
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if (n == right_len) return(conc -> right);
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return(CORD_substr_checked(conc -> right, i - left_len, n));
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} else if (i+n <= left_len) {
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if (n == left_len) return(conc -> left);
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return(CORD_substr_checked(conc -> left, i, n));
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} else {
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/* Need at least one character from each side. */
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register CORD left_part;
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register CORD right_part;
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register size_t left_part_len = left_len - i;
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if (i == 0) {
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left_part = conc -> left;
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} else {
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left_part = CORD_substr_checked(conc -> left, i, left_part_len);
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}
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if (i + n == right_len + left_len) {
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right_part = conc -> right;
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} else {
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right_part = CORD_substr_checked(conc -> right, 0,
|
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n - left_part_len);
|
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}
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return(CORD_cat(left_part, right_part));
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}
|
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} else /* function */ {
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if (n > SUBSTR_LIMIT) {
|
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if (IS_SUBSTR(x)) {
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/* Avoid nesting substring nodes. */
|
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register struct Function * f = &(((CordRep *)x) -> function);
|
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register struct substr_args *descr =
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(struct substr_args *)(f -> client_data);
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return(CORD_substr_closure((CORD)descr->sa_cord,
|
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i + descr->sa_index,
|
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n, f -> fn));
|
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} else {
|
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return(CORD_substr_closure(x, i, n, CORD_apply_access_fn));
|
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}
|
||||
} else {
|
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char * result;
|
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register struct Function * f = &(((CordRep *)x) -> function);
|
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char buf[SUBSTR_LIMIT+1];
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register char * p = buf;
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register char c;
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register int j;
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register int lim = i + n;
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|
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for (j = i; j < lim; j++) {
|
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c = (*(f -> fn))(j, f -> client_data);
|
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if (c == '\0') {
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return(CORD_substr_closure(x, i, n, CORD_apply_access_fn));
|
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}
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*p++ = c;
|
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}
|
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*p = '\0';
|
||||
result = GC_MALLOC_ATOMIC(n+1);
|
||||
if (result == 0) OUT_OF_MEMORY;
|
||||
strcpy(result, buf);
|
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return(result);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
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CORD CORD_substr(CORD x, size_t i, size_t n)
|
||||
{
|
||||
register size_t len = CORD_len(x);
|
||||
|
||||
if (i >= len || n <= 0) return(0);
|
||||
/* n < 0 is impossible in a correct C implementation, but */
|
||||
/* quite possible under SunOS 4.X. */
|
||||
if (i + n > len) n = len - i;
|
||||
# ifndef __STDC__
|
||||
if (i < 0) ABORT("CORD_substr: second arg. negative");
|
||||
/* Possible only if both client and C implementation are buggy. */
|
||||
/* But empirically this happens frequently. */
|
||||
# endif
|
||||
return(CORD_substr_checked(x, i, n));
|
||||
}
|
||||
|
||||
/* See cord.h for definition. We assume i is in range. */
|
||||
int CORD_iter5(CORD x, size_t i, CORD_iter_fn f1,
|
||||
CORD_batched_iter_fn f2, void * client_data)
|
||||
{
|
||||
if (x == 0) return(0);
|
||||
if (CORD_IS_STRING(x)) {
|
||||
register const char *p = x+i;
|
||||
|
||||
if (*p == '\0') ABORT("2nd arg to CORD_iter5 too big");
|
||||
if (f2 != CORD_NO_FN) {
|
||||
return((*f2)(p, client_data));
|
||||
} else {
|
||||
while (*p) {
|
||||
if ((*f1)(*p, client_data)) return(1);
|
||||
p++;
|
||||
}
|
||||
return(0);
|
||||
}
|
||||
} else if (IS_CONCATENATION(x)) {
|
||||
register struct Concatenation * conc
|
||||
= &(((CordRep *)x) -> concatenation);
|
||||
|
||||
|
||||
if (i > 0) {
|
||||
register size_t left_len = LEFT_LEN(conc);
|
||||
|
||||
if (i >= left_len) {
|
||||
return(CORD_iter5(conc -> right, i - left_len, f1, f2,
|
||||
client_data));
|
||||
}
|
||||
}
|
||||
if (CORD_iter5(conc -> left, i, f1, f2, client_data)) {
|
||||
return(1);
|
||||
}
|
||||
return(CORD_iter5(conc -> right, 0, f1, f2, client_data));
|
||||
} else /* function */ {
|
||||
register struct Function * f = &(((CordRep *)x) -> function);
|
||||
register size_t j;
|
||||
register size_t lim = f -> len;
|
||||
|
||||
for (j = i; j < lim; j++) {
|
||||
if ((*f1)((*(f -> fn))(j, f -> client_data), client_data)) {
|
||||
return(1);
|
||||
}
|
||||
}
|
||||
return(0);
|
||||
}
|
||||
}
|
||||
|
||||
#undef CORD_iter
|
||||
int CORD_iter(CORD x, CORD_iter_fn f1, void * client_data)
|
||||
{
|
||||
return(CORD_iter5(x, 0, f1, CORD_NO_FN, client_data));
|
||||
}
|
||||
|
||||
int CORD_riter4(CORD x, size_t i, CORD_iter_fn f1, void * client_data)
|
||||
{
|
||||
if (x == 0) return(0);
|
||||
if (CORD_IS_STRING(x)) {
|
||||
register const char *p = x + i;
|
||||
register char c;
|
||||
|
||||
for(;;) {
|
||||
c = *p;
|
||||
if (c == '\0') ABORT("2nd arg to CORD_riter4 too big");
|
||||
if ((*f1)(c, client_data)) return(1);
|
||||
if (p == x) break;
|
||||
p--;
|
||||
}
|
||||
return(0);
|
||||
} else if (IS_CONCATENATION(x)) {
|
||||
register struct Concatenation * conc
|
||||
= &(((CordRep *)x) -> concatenation);
|
||||
register CORD left_part = conc -> left;
|
||||
register size_t left_len;
|
||||
|
||||
left_len = LEFT_LEN(conc);
|
||||
if (i >= left_len) {
|
||||
if (CORD_riter4(conc -> right, i - left_len, f1, client_data)) {
|
||||
return(1);
|
||||
}
|
||||
return(CORD_riter4(left_part, left_len - 1, f1, client_data));
|
||||
} else {
|
||||
return(CORD_riter4(left_part, i, f1, client_data));
|
||||
}
|
||||
} else /* function */ {
|
||||
register struct Function * f = &(((CordRep *)x) -> function);
|
||||
register size_t j;
|
||||
|
||||
for (j = i; ; j--) {
|
||||
if ((*f1)((*(f -> fn))(j, f -> client_data), client_data)) {
|
||||
return(1);
|
||||
}
|
||||
if (j == 0) return(0);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
int CORD_riter(CORD x, CORD_iter_fn f1, void * client_data)
|
||||
{
|
||||
return(CORD_riter4(x, CORD_len(x) - 1, f1, client_data));
|
||||
}
|
||||
|
||||
/*
|
||||
* The following functions are concerned with balancing cords.
|
||||
* Strategy:
|
||||
* Scan the cord from left to right, keeping the cord scanned so far
|
||||
* as a forest of balanced trees of exponentialy decreasing length.
|
||||
* When a new subtree needs to be added to the forest, we concatenate all
|
||||
* shorter ones to the new tree in the appropriate order, and then insert
|
||||
* the result into the forest.
|
||||
* Crucial invariants:
|
||||
* 1. The concatenation of the forest (in decreasing order) with the
|
||||
* unscanned part of the rope is equal to the rope being balanced.
|
||||
* 2. All trees in the forest are balanced.
|
||||
* 3. forest[i] has depth at most i.
|
||||
*/
|
||||
|
||||
typedef struct {
|
||||
CORD c;
|
||||
size_t len; /* Actual length of c */
|
||||
} ForestElement;
|
||||
|
||||
static size_t min_len [ MAX_DEPTH ];
|
||||
|
||||
static int min_len_init = 0;
|
||||
|
||||
int CORD_max_len;
|
||||
|
||||
typedef ForestElement Forest [ MAX_DEPTH ];
|
||||
/* forest[i].len >= fib(i+1) */
|
||||
/* The string is the concatenation */
|
||||
/* of the forest in order of DECREASING */
|
||||
/* indices. */
|
||||
|
||||
void CORD_init_min_len()
|
||||
{
|
||||
register int i;
|
||||
register size_t last, previous, current;
|
||||
|
||||
min_len[0] = previous = 1;
|
||||
min_len[1] = last = 2;
|
||||
for (i = 2; i < MAX_DEPTH; i++) {
|
||||
current = last + previous;
|
||||
if (current < last) /* overflow */ current = last;
|
||||
min_len[i] = current;
|
||||
previous = last;
|
||||
last = current;
|
||||
}
|
||||
CORD_max_len = last - 1;
|
||||
min_len_init = 1;
|
||||
}
|
||||
|
||||
|
||||
void CORD_init_forest(ForestElement * forest, size_t max_len)
|
||||
{
|
||||
register int i;
|
||||
|
||||
for (i = 0; i < MAX_DEPTH; i++) {
|
||||
forest[i].c = 0;
|
||||
if (min_len[i] > max_len) return;
|
||||
}
|
||||
ABORT("Cord too long");
|
||||
}
|
||||
|
||||
/* Add a leaf to the appropriate level in the forest, cleaning */
|
||||
/* out lower levels as necessary. */
|
||||
/* Also works if x is a balanced tree of concatenations; however */
|
||||
/* in this case an extra concatenation node may be inserted above x; */
|
||||
/* This node should not be counted in the statement of the invariants. */
|
||||
void CORD_add_forest(ForestElement * forest, CORD x, size_t len)
|
||||
{
|
||||
register int i = 0;
|
||||
register CORD sum = CORD_EMPTY;
|
||||
register size_t sum_len = 0;
|
||||
|
||||
while (len > min_len[i + 1]) {
|
||||
if (forest[i].c != 0) {
|
||||
sum = CORD_cat(forest[i].c, sum);
|
||||
sum_len += forest[i].len;
|
||||
forest[i].c = 0;
|
||||
}
|
||||
i++;
|
||||
}
|
||||
/* Sum has depth at most 1 greter than what would be required */
|
||||
/* for balance. */
|
||||
sum = CORD_cat(sum, x);
|
||||
sum_len += len;
|
||||
/* If x was a leaf, then sum is now balanced. To see this */
|
||||
/* consider the two cases in which forest[i-1] either is or is */
|
||||
/* not empty. */
|
||||
while (sum_len >= min_len[i]) {
|
||||
if (forest[i].c != 0) {
|
||||
sum = CORD_cat(forest[i].c, sum);
|
||||
sum_len += forest[i].len;
|
||||
/* This is again balanced, since sum was balanced, and has */
|
||||
/* allowable depth that differs from i by at most 1. */
|
||||
forest[i].c = 0;
|
||||
}
|
||||
i++;
|
||||
}
|
||||
i--;
|
||||
forest[i].c = sum;
|
||||
forest[i].len = sum_len;
|
||||
}
|
||||
|
||||
CORD CORD_concat_forest(ForestElement * forest, size_t expected_len)
|
||||
{
|
||||
register int i = 0;
|
||||
CORD sum = 0;
|
||||
size_t sum_len = 0;
|
||||
|
||||
while (sum_len != expected_len) {
|
||||
if (forest[i].c != 0) {
|
||||
sum = CORD_cat(forest[i].c, sum);
|
||||
sum_len += forest[i].len;
|
||||
}
|
||||
i++;
|
||||
}
|
||||
return(sum);
|
||||
}
|
||||
|
||||
/* Insert the frontier of x into forest. Balanced subtrees are */
|
||||
/* treated as leaves. This potentially adds one to the depth */
|
||||
/* of the final tree. */
|
||||
void CORD_balance_insert(CORD x, size_t len, ForestElement * forest)
|
||||
{
|
||||
register int depth;
|
||||
|
||||
if (CORD_IS_STRING(x)) {
|
||||
CORD_add_forest(forest, x, len);
|
||||
} else if (IS_CONCATENATION(x)
|
||||
&& ((depth = DEPTH(x)) >= MAX_DEPTH
|
||||
|| len < min_len[depth])) {
|
||||
register struct Concatenation * conc
|
||||
= &(((CordRep *)x) -> concatenation);
|
||||
size_t left_len = LEFT_LEN(conc);
|
||||
|
||||
CORD_balance_insert(conc -> left, left_len, forest);
|
||||
CORD_balance_insert(conc -> right, len - left_len, forest);
|
||||
} else /* function or balanced */ {
|
||||
CORD_add_forest(forest, x, len);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
CORD CORD_balance(CORD x)
|
||||
{
|
||||
Forest forest;
|
||||
register size_t len;
|
||||
|
||||
if (x == 0) return(0);
|
||||
if (CORD_IS_STRING(x)) return(x);
|
||||
if (!min_len_init) CORD_init_min_len();
|
||||
len = LEN(x);
|
||||
CORD_init_forest(forest, len);
|
||||
CORD_balance_insert(x, len, forest);
|
||||
return(CORD_concat_forest(forest, len));
|
||||
}
|
||||
|
||||
|
||||
/* Position primitives */
|
||||
|
||||
/* Private routines to deal with the hard cases only: */
|
||||
|
||||
/* P contains a prefix of the path to cur_pos. Extend it to a full */
|
||||
/* path and set up leaf info. */
|
||||
/* Return 0 if past the end of cord, 1 o.w. */
|
||||
void CORD__extend_path(register CORD_pos p)
|
||||
{
|
||||
register struct CORD_pe * current_pe = &(p[0].path[p[0].path_len]);
|
||||
register CORD top = current_pe -> pe_cord;
|
||||
register size_t pos = p[0].cur_pos;
|
||||
register size_t top_pos = current_pe -> pe_start_pos;
|
||||
register size_t top_len = GEN_LEN(top);
|
||||
|
||||
/* Fill in the rest of the path. */
|
||||
while(!CORD_IS_STRING(top) && IS_CONCATENATION(top)) {
|
||||
register struct Concatenation * conc =
|
||||
&(((CordRep *)top) -> concatenation);
|
||||
register size_t left_len;
|
||||
|
||||
left_len = LEFT_LEN(conc);
|
||||
current_pe++;
|
||||
if (pos >= top_pos + left_len) {
|
||||
current_pe -> pe_cord = top = conc -> right;
|
||||
current_pe -> pe_start_pos = top_pos = top_pos + left_len;
|
||||
top_len -= left_len;
|
||||
} else {
|
||||
current_pe -> pe_cord = top = conc -> left;
|
||||
current_pe -> pe_start_pos = top_pos;
|
||||
top_len = left_len;
|
||||
}
|
||||
p[0].path_len++;
|
||||
}
|
||||
/* Fill in leaf description for fast access. */
|
||||
if (CORD_IS_STRING(top)) {
|
||||
p[0].cur_leaf = top;
|
||||
p[0].cur_start = top_pos;
|
||||
p[0].cur_end = top_pos + top_len;
|
||||
} else {
|
||||
p[0].cur_end = 0;
|
||||
}
|
||||
if (pos >= top_pos + top_len) p[0].path_len = CORD_POS_INVALID;
|
||||
}
|
||||
|
||||
char CORD__pos_fetch(register CORD_pos p)
|
||||
{
|
||||
/* Leaf is a function node */
|
||||
struct CORD_pe * pe = &((p)[0].path[(p)[0].path_len]);
|
||||
CORD leaf = pe -> pe_cord;
|
||||
register struct Function * f = &(((CordRep *)leaf) -> function);
|
||||
|
||||
if (!IS_FUNCTION(leaf)) ABORT("CORD_pos_fetch: bad leaf");
|
||||
return ((*(f -> fn))(p[0].cur_pos - pe -> pe_start_pos, f -> client_data));
|
||||
}
|
||||
|
||||
void CORD__next(register CORD_pos p)
|
||||
{
|
||||
register size_t cur_pos = p[0].cur_pos + 1;
|
||||
register struct CORD_pe * current_pe = &((p)[0].path[(p)[0].path_len]);
|
||||
register CORD leaf = current_pe -> pe_cord;
|
||||
|
||||
/* Leaf is not a string or we're at end of leaf */
|
||||
p[0].cur_pos = cur_pos;
|
||||
if (!CORD_IS_STRING(leaf)) {
|
||||
/* Function leaf */
|
||||
register struct Function * f = &(((CordRep *)leaf) -> function);
|
||||
register size_t start_pos = current_pe -> pe_start_pos;
|
||||
register size_t end_pos = start_pos + f -> len;
|
||||
|
||||
if (cur_pos < end_pos) {
|
||||
/* Fill cache and return. */
|
||||
register size_t i;
|
||||
register size_t limit = cur_pos + FUNCTION_BUF_SZ;
|
||||
register CORD_fn fn = f -> fn;
|
||||
register void * client_data = f -> client_data;
|
||||
|
||||
if (limit > end_pos) {
|
||||
limit = end_pos;
|
||||
}
|
||||
for (i = cur_pos; i < limit; i++) {
|
||||
p[0].function_buf[i - cur_pos] =
|
||||
(*fn)(i - start_pos, client_data);
|
||||
}
|
||||
p[0].cur_start = cur_pos;
|
||||
p[0].cur_leaf = p[0].function_buf;
|
||||
p[0].cur_end = limit;
|
||||
return;
|
||||
}
|
||||
}
|
||||
/* End of leaf */
|
||||
/* Pop the stack until we find two concatenation nodes with the */
|
||||
/* same start position: this implies we were in left part. */
|
||||
{
|
||||
while (p[0].path_len > 0
|
||||
&& current_pe[0].pe_start_pos != current_pe[-1].pe_start_pos) {
|
||||
p[0].path_len--;
|
||||
current_pe--;
|
||||
}
|
||||
if (p[0].path_len == 0) {
|
||||
p[0].path_len = CORD_POS_INVALID;
|
||||
return;
|
||||
}
|
||||
}
|
||||
p[0].path_len--;
|
||||
CORD__extend_path(p);
|
||||
}
|
||||
|
||||
void CORD__prev(register CORD_pos p)
|
||||
{
|
||||
register struct CORD_pe * pe = &(p[0].path[p[0].path_len]);
|
||||
|
||||
if (p[0].cur_pos == 0) {
|
||||
p[0].path_len = CORD_POS_INVALID;
|
||||
return;
|
||||
}
|
||||
p[0].cur_pos--;
|
||||
if (p[0].cur_pos >= pe -> pe_start_pos) return;
|
||||
|
||||
/* Beginning of leaf */
|
||||
|
||||
/* Pop the stack until we find two concatenation nodes with the */
|
||||
/* different start position: this implies we were in right part. */
|
||||
{
|
||||
register struct CORD_pe * current_pe = &((p)[0].path[(p)[0].path_len]);
|
||||
|
||||
while (p[0].path_len > 0
|
||||
&& current_pe[0].pe_start_pos == current_pe[-1].pe_start_pos) {
|
||||
p[0].path_len--;
|
||||
current_pe--;
|
||||
}
|
||||
}
|
||||
p[0].path_len--;
|
||||
CORD__extend_path(p);
|
||||
}
|
||||
|
||||
#undef CORD_pos_fetch
|
||||
#undef CORD_next
|
||||
#undef CORD_prev
|
||||
#undef CORD_pos_to_index
|
||||
#undef CORD_pos_to_cord
|
||||
#undef CORD_pos_valid
|
||||
|
||||
char CORD_pos_fetch(register CORD_pos p)
|
||||
{
|
||||
if (p[0].cur_start <= p[0].cur_pos && p[0].cur_pos < p[0].cur_end) {
|
||||
return(p[0].cur_leaf[p[0].cur_pos - p[0].cur_start]);
|
||||
} else {
|
||||
return(CORD__pos_fetch(p));
|
||||
}
|
||||
}
|
||||
|
||||
void CORD_next(CORD_pos p)
|
||||
{
|
||||
if (p[0].cur_pos < p[0].cur_end - 1) {
|
||||
p[0].cur_pos++;
|
||||
} else {
|
||||
CORD__next(p);
|
||||
}
|
||||
}
|
||||
|
||||
void CORD_prev(CORD_pos p)
|
||||
{
|
||||
if (p[0].cur_end != 0 && p[0].cur_pos > p[0].cur_start) {
|
||||
p[0].cur_pos--;
|
||||
} else {
|
||||
CORD__prev(p);
|
||||
}
|
||||
}
|
||||
|
||||
size_t CORD_pos_to_index(CORD_pos p)
|
||||
{
|
||||
return(p[0].cur_pos);
|
||||
}
|
||||
|
||||
CORD CORD_pos_to_cord(CORD_pos p)
|
||||
{
|
||||
return(p[0].path[0].pe_cord);
|
||||
}
|
||||
|
||||
int CORD_pos_valid(CORD_pos p)
|
||||
{
|
||||
return(p[0].path_len != CORD_POS_INVALID);
|
||||
}
|
||||
|
||||
void CORD_set_pos(CORD_pos p, CORD x, size_t i)
|
||||
{
|
||||
if (x == CORD_EMPTY) {
|
||||
p[0].path_len = CORD_POS_INVALID;
|
||||
return;
|
||||
}
|
||||
p[0].path[0].pe_cord = x;
|
||||
p[0].path[0].pe_start_pos = 0;
|
||||
p[0].path_len = 0;
|
||||
p[0].cur_pos = i;
|
||||
CORD__extend_path(p);
|
||||
}
|
||||
Reference in New Issue
Block a user