69 lines
1.6 KiB
C
69 lines
1.6 KiB
C
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/* $Revision: 1.7 $
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*/
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/* `Buffer' is a dynamically growing, general-purpose buffer data
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* structure.
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*
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* buffer_new(size) -- returns new buffer with initial size `size'
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* or some default size if argument is zero
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* buffer_delete(b) -- marks a buffer as unused
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* buffer_clear(b) -- empties a buffer
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* buffer_puts(b,data,len) -- appends data to a buffer, growing it if
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* necessary
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* buffer_putc(b,c) -- appends a character to a buffer
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*/
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#include "unroff.h"
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static int sizeinc_linear(Buffer *);
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static Buffer *first_free;
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Buffer *buffer_new(int size) {
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Buffer *p;
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if (size == 0)
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size = 512;
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if (first_free) { /* reuse a buffer if there is one */
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p = first_free;
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first_free = p->next;
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if (p->max < size) {
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free(p->data);
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p->data = safe_malloc(p->max = size);
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}
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} else {
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p = safe_malloc(sizeof *p);
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p->data = safe_malloc(size);
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p->increment = p->max = size;
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p->sizeinc_func = sizeinc_linear;
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}
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buffer_clear(p);
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return p;
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}
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void buffer_delete(Buffer *p) {
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assert(p->size >= 0);
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p->size = -1;
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p->next = first_free;
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first_free = p;
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}
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void buffer_grow(Buffer *p) {
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p->max = p->sizeinc_func(p);
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p->data = safe_realloc(p->data, p->max);
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}
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void buffer_puts(Buffer *p, char *s, int size) {
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assert(size >= 0);
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while (p->size + size > p->max)
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buffer_grow(p);
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if (size == 0)
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return;
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memcpy(p->data+p->size, s, size);
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p->size += size;
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}
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static int sizeinc_linear(Buffer *p) {
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return p->max + p->increment;
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}
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