| /* |
| * 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. |
| * |
| * Author: Hans-J. Boehm (boehm@parc.xerox.com) |
| */ |
| /* Boehm, October 3, 1994 5:19 pm PDT */ |
| # include "gc.h" |
| # include "cord.h" |
| # include <stdlib.h> |
| # include <stdio.h> |
| # include <string.h> |
| |
| /* An implementation of the cord primitives. These are the only */ |
| /* Functions that understand the representation. We perform only */ |
| /* minimal checks on arguments to these functions. Out of bounds */ |
| /* arguments to the iteration functions may result in client functions */ |
| /* invoked on garbage data. In most cases, client functions should be */ |
| /* programmed defensively enough that this does not result in memory */ |
| /* smashes. */ |
| |
| typedef void (* oom_fn)(void); |
| |
| oom_fn CORD_oom_fn = (oom_fn) 0; |
| |
| # define OUT_OF_MEMORY { if (CORD_oom_fn != (oom_fn) 0) (*CORD_oom_fn)(); \ |
| ABORT("Out of memory\n"); } |
| # define ABORT(msg) { fprintf(stderr, "%s\n", msg); abort(); } |
| |
| typedef unsigned long word; |
| |
| typedef union { |
| struct Concatenation { |
| char null; |
| char header; |
| char depth; /* concatenation nesting depth. */ |
| unsigned char left_len; |
| /* Length of left child if it is sufficiently */ |
| /* short; 0 otherwise. */ |
| # define MAX_LEFT_LEN 255 |
| word len; |
| CORD left; /* length(left) > 0 */ |
| CORD right; /* length(right) > 0 */ |
| } concatenation; |
| struct Function { |
| char null; |
| char header; |
| char depth; /* always 0 */ |
| char left_len; /* always 0 */ |
| word len; |
| CORD_fn fn; |
| void * client_data; |
| } function; |
| struct Generic { |
| char null; |
| char header; |
| char depth; |
| char left_len; |
| word len; |
| } generic; |
| char string[1]; |
| } CordRep; |
| |
| # define CONCAT_HDR 1 |
| |
| # define FN_HDR 4 |
| # define SUBSTR_HDR 6 |
| /* Substring nodes are a special case of function nodes. */ |
| /* The client_data field is known to point to a substr_args */ |
| /* structure, and the function is either CORD_apply_access_fn */ |
| /* or CORD_index_access_fn. */ |
| |
| /* The following may be applied only to function and concatenation nodes: */ |
| #define IS_CONCATENATION(s) (((CordRep *)s)->generic.header == CONCAT_HDR) |
| |
| #define IS_FUNCTION(s) ((((CordRep *)s)->generic.header & FN_HDR) != 0) |
| |
| #define IS_SUBSTR(s) (((CordRep *)s)->generic.header == SUBSTR_HDR) |
| |
| #define LEN(s) (((CordRep *)s) -> generic.len) |
| #define DEPTH(s) (((CordRep *)s) -> generic.depth) |
| #define GEN_LEN(s) (CORD_IS_STRING(s) ? strlen(s) : LEN(s)) |
| |
| #define LEFT_LEN(c) ((c) -> left_len != 0? \ |
| (c) -> left_len \ |
| : (CORD_IS_STRING((c) -> left) ? \ |
| (c) -> len - GEN_LEN((c) -> right) \ |
| : LEN((c) -> left))) |
| |
| #define SHORT_LIMIT (sizeof(CordRep) - 1) |
| /* Cords shorter than this are C strings */ |
| |
| |
| /* Dump the internal representation of x to stdout, with initial */ |
| /* indentation level n. */ |
| void CORD_dump_inner(CORD x, unsigned n) |
| { |
| register size_t i; |
| |
| for (i = 0; i < (size_t)n; i++) { |
| fputs(" ", stdout); |
| } |
| if (x == 0) { |
| fputs("NIL\n", stdout); |
| } else if (CORD_IS_STRING(x)) { |
| for (i = 0; i <= SHORT_LIMIT; i++) { |
| if (x[i] == '\0') break; |
| putchar(x[i]); |
| } |
| if (x[i] != '\0') fputs("...", stdout); |
| putchar('\n'); |
| } else if (IS_CONCATENATION(x)) { |
| register struct Concatenation * conc = |
| &(((CordRep *)x) -> concatenation); |
| printf("Concatenation: %p (len: %d, depth: %d)\n", |
| x, (int)(conc -> len), (int)(conc -> depth)); |
| CORD_dump_inner(conc -> left, n+1); |
| CORD_dump_inner(conc -> right, n+1); |
| } else /* function */{ |
| register struct Function * func = |
| &(((CordRep *)x) -> function); |
| if (IS_SUBSTR(x)) printf("(Substring) "); |
| printf("Function: %p (len: %d): ", x, (int)(func -> len)); |
| for (i = 0; i < 20 && i < func -> len; i++) { |
| putchar((*(func -> fn))(i, func -> client_data)); |
| } |
| if (i < func -> len) fputs("...", stdout); |
| putchar('\n'); |
| } |
| } |
| |
| /* Dump the internal representation of x to stdout */ |
| void CORD_dump(CORD x) |
| { |
| CORD_dump_inner(x, 0); |
| fflush(stdout); |
| } |
| |
| CORD CORD_cat_char_star(CORD x, const char * y, size_t leny) |
| { |
| register size_t result_len; |
| register size_t lenx; |
| register int depth; |
| |
| if (x == CORD_EMPTY) return(y); |
| if (leny == 0) return(x); |
| if (CORD_IS_STRING(x)) { |
| lenx = strlen(x); |
| result_len = lenx + leny; |
| if (result_len <= SHORT_LIMIT) { |
| register char * result = GC_MALLOC_ATOMIC(result_len+1); |
| |
| if (result == 0) OUT_OF_MEMORY; |
| memcpy(result, x, lenx); |
| memcpy(result + lenx, y, leny); |
| result[result_len] = '\0'; |
| return((CORD) result); |
| } else { |
| depth = 1; |
| } |
| } else { |
| register CORD right; |
| register CORD left; |
| register char * new_right; |
| register size_t right_len; |
| |
| lenx = LEN(x); |
| |
| if (leny <= SHORT_LIMIT/2 |
| && IS_CONCATENATION(x) |
| && CORD_IS_STRING(right = ((CordRep *)x) -> concatenation.right)) { |
| /* Merge y into right part of x. */ |
| if (!CORD_IS_STRING(left = ((CordRep *)x) -> concatenation.left)) { |
| right_len = lenx - LEN(left); |
| } else if (((CordRep *)x) -> concatenation.left_len != 0) { |
| right_len = lenx - ((CordRep *)x) -> concatenation.left_len; |
| } else { |
| right_len = strlen(right); |
| } |
| result_len = right_len + leny; /* length of new_right */ |
| if (result_len <= SHORT_LIMIT) { |
| new_right = GC_MALLOC_ATOMIC(result_len + 1); |
| memcpy(new_right, right, right_len); |
| memcpy(new_right + right_len, y, leny); |
| new_right[result_len] = '\0'; |
| y = new_right; |
| leny = result_len; |
| x = left; |
| lenx -= right_len; |
| /* Now fall through to concatenate the two pieces: */ |
| } |
| if (CORD_IS_STRING(x)) { |
| depth = 1; |
| } else { |
| depth = DEPTH(x) + 1; |
| } |
| } else { |
| depth = DEPTH(x) + 1; |
| } |
| result_len = lenx + leny; |
| } |
| { |
| /* The general case; lenx, result_len is known: */ |
| register struct Concatenation * result; |
| |
| result = GC_NEW(struct Concatenation); |
| if (result == 0) OUT_OF_MEMORY; |
| result->header = CONCAT_HDR; |
| result->depth = depth; |
| if (lenx <= MAX_LEFT_LEN) result->left_len = lenx; |
| result->len = result_len; |
| result->left = x; |
| result->right = y; |
| if (depth >= MAX_DEPTH) { |
| return(CORD_balance((CORD)result)); |
| } else { |
| return((CORD) result); |
| } |
| } |
| } |
| |
| |
| CORD CORD_cat(CORD x, CORD y) |
| { |
| register size_t result_len; |
| register int depth; |
| register size_t lenx; |
| |
| if (x == CORD_EMPTY) return(y); |
| if (y == CORD_EMPTY) return(x); |
| if (CORD_IS_STRING(y)) { |
| return(CORD_cat_char_star(x, y, strlen(y))); |
| } else if (CORD_IS_STRING(x)) { |
| lenx = strlen(x); |
| depth = DEPTH(y) + 1; |
| } else { |
| register int depthy = DEPTH(y); |
| |
| lenx = LEN(x); |
| depth = DEPTH(x) + 1; |
| if (depthy >= depth) depth = depthy + 1; |
| } |
| result_len = lenx + LEN(y); |
| { |
| register struct Concatenation * result; |
| |
| result = GC_NEW(struct Concatenation); |
| if (result == 0) OUT_OF_MEMORY; |
| result->header = CONCAT_HDR; |
| result->depth = depth; |
| if (lenx <= MAX_LEFT_LEN) result->left_len = lenx; |
| result->len = result_len; |
| result->left = x; |
| result->right = y; |
| if (depth >= MAX_DEPTH) { |
| return(CORD_balance((CORD)result)); |
| } else { |
| return((CORD) result); |
| } |
| } |
| } |
| |
| |
| |
| CORD CORD_from_fn(CORD_fn fn, void * client_data, size_t len) |
| { |
| if (len <= 0) return(0); |
| if (len <= SHORT_LIMIT) { |
| register char * result; |
| register size_t i; |
| char buf[SHORT_LIMIT+1]; |
| register char c; |
| |
| for (i = 0; i < len; i++) { |
| c = (*fn)(i, client_data); |
| if (c == '\0') goto gen_case; |
| buf[i] = c; |
| } |
| buf[i] = '\0'; |
| result = GC_MALLOC_ATOMIC(len+1); |
| if (result == 0) OUT_OF_MEMORY; |
| strcpy(result, buf); |
| result[len] = '\0'; |
| return((CORD) result); |
| } |
| gen_case: |
| { |
| register struct Function * result; |
| |
| result = GC_NEW(struct Function); |
| if (result == 0) OUT_OF_MEMORY; |
| result->header = FN_HDR; |
| /* depth is already 0 */ |
| result->len = len; |
| result->fn = fn; |
| result->client_data = client_data; |
| return((CORD) result); |
| } |
| } |
| |
| size_t CORD_len(CORD x) |
| { |
| if (x == 0) { |
| return(0); |
| } else { |
| return(GEN_LEN(x)); |
| } |
| } |
| |
| struct substr_args { |
| CordRep * sa_cord; |
| size_t sa_index; |
| }; |
| |
| char CORD_index_access_fn(size_t i, void * client_data) |
| { |
| register struct substr_args *descr = (struct substr_args *)client_data; |
| |
| return(((char *)(descr->sa_cord))[i + descr->sa_index]); |
| } |
| |
| char CORD_apply_access_fn(size_t i, void * client_data) |
| { |
| register struct substr_args *descr = (struct substr_args *)client_data; |
| register struct Function * fn_cord = &(descr->sa_cord->function); |
| |
| return((*(fn_cord->fn))(i + descr->sa_index, fn_cord->client_data)); |
| } |
| |
| /* A version of CORD_substr that simply returns a function node, thus */ |
| /* postponing its work. The fourth argument is a function that may */ |
| /* be used for efficient access to the ith character. */ |
| /* Assumes i >= 0 and i + n < length(x). */ |
| CORD CORD_substr_closure(CORD x, size_t i, size_t n, CORD_fn f) |
| { |
| register struct substr_args * sa = GC_NEW(struct substr_args); |
| CORD result; |
| |
| if (sa == 0) OUT_OF_MEMORY; |
| sa->sa_cord = (CordRep *)x; |
| sa->sa_index = i; |
| result = CORD_from_fn(f, (void *)sa, n); |
| ((CordRep *)result) -> function.header = SUBSTR_HDR; |
| return (result); |
| } |
| |
| # define SUBSTR_LIMIT (10 * SHORT_LIMIT) |
| /* Substrings of function nodes and flat strings shorter than */ |
| /* this are flat strings. Othewise we use a functional */ |
| /* representation, which is significantly slower to access. */ |
| |
| /* A version of CORD_substr that assumes i >= 0, n > 0, and i + n < length(x).*/ |
| CORD CORD_substr_checked(CORD x, size_t i, size_t n) |
| { |
| if (CORD_IS_STRING(x)) { |
| if (n > SUBSTR_LIMIT) { |
| return(CORD_substr_closure(x, i, n, CORD_index_access_fn)); |
| } else { |
| register char * result = GC_MALLOC_ATOMIC(n+1); |
| |
| if (result == 0) OUT_OF_MEMORY; |
| strncpy(result, x+i, n); |
| result[n] = '\0'; |
| return(result); |
| } |
| } else if (IS_CONCATENATION(x)) { |
| register struct Concatenation * conc |
| = &(((CordRep *)x) -> concatenation); |
| register size_t left_len; |
| register size_t right_len; |
| |
| left_len = LEFT_LEN(conc); |
| right_len = conc -> len - left_len; |
| if (i >= left_len) { |
| if (n == right_len) return(conc -> right); |
| return(CORD_substr_checked(conc -> right, i - left_len, n)); |
| } else if (i+n <= left_len) { |
| if (n == left_len) return(conc -> left); |
| return(CORD_substr_checked(conc -> left, i, n)); |
| } else { |
| /* Need at least one character from each side. */ |
| register CORD left_part; |
| register CORD right_part; |
| register size_t left_part_len = left_len - i; |
| |
| if (i == 0) { |
| left_part = conc -> left; |
| } else { |
| left_part = CORD_substr_checked(conc -> left, i, left_part_len); |
| } |
| if (i + n == right_len + left_len) { |
| right_part = conc -> right; |
| } else { |
| right_part = CORD_substr_checked(conc -> right, 0, |
| n - left_part_len); |
| } |
| return(CORD_cat(left_part, right_part)); |
| } |
| } else /* function */ { |
| if (n > SUBSTR_LIMIT) { |
| if (IS_SUBSTR(x)) { |
| /* Avoid nesting substring nodes. */ |
| register struct Function * f = &(((CordRep *)x) -> function); |
| register struct substr_args *descr = |
| (struct substr_args *)(f -> client_data); |
| |
| return(CORD_substr_closure((CORD)descr->sa_cord, |
| i + descr->sa_index, |
| n, f -> fn)); |
| } else { |
| return(CORD_substr_closure(x, i, n, CORD_apply_access_fn)); |
| } |
| } else { |
| char * result; |
| register struct Function * f = &(((CordRep *)x) -> function); |
| char buf[SUBSTR_LIMIT+1]; |
| register char * p = buf; |
| register char c; |
| register int j; |
| register int lim = i + n; |
| |
| for (j = i; j < lim; j++) { |
| c = (*(f -> fn))(j, f -> client_data); |
| if (c == '\0') { |
| return(CORD_substr_closure(x, i, n, CORD_apply_access_fn)); |
| } |
| *p++ = c; |
| } |
| *p = '\0'; |
| result = GC_MALLOC_ATOMIC(n+1); |
| if (result == 0) OUT_OF_MEMORY; |
| strcpy(result, buf); |
| return(result); |
| } |
| } |
| } |
| |
| 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); |
| } |
