--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/extract/src/alloc.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,119 @@
+#include "extract/alloc.h"
+
+#include <assert.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+struct extract_alloc_t
+{
+	extract_realloc_fn_t     *realloc_fn;
+	extract_caller_context_t *realloc_state;
+	size_t                    exp_min_alloc_size;
+	extract_alloc_stats_t     stats;
+};
+
+int
+extract_alloc_create(	extract_realloc_fn_t *realloc_fn,
+			void     *realloc_state,
+			extract_alloc_t  **palloc)
+{
+	assert(realloc_fn);
+	assert(palloc);
+	*palloc = realloc_fn(realloc_state, NULL /*ptr*/, sizeof(**palloc));
+	if (!*palloc) {
+		errno = ENOMEM;
+		return -1;
+	}
+	memset(*palloc, 0, sizeof(**palloc));
+	(*palloc)->realloc_fn = realloc_fn;
+	(*palloc)->realloc_state = realloc_state;
+	(*palloc)->exp_min_alloc_size = 0;
+	return 0;
+}
+
+void extract_alloc_destroy(extract_alloc_t **palloc)
+{
+	if (!*palloc) return;
+	(*palloc)->realloc_fn((*palloc)->realloc_state, *palloc, 0 /*newsize*/);
+	*palloc = NULL;
+}
+
+extract_alloc_stats_t *extract_alloc_stats(extract_alloc_t *alloc)
+{
+	return &alloc->stats;
+}
+
+static size_t round_up(extract_alloc_t *alloc, size_t n)
+{
+	size_t ret;
+
+	if (alloc == NULL || alloc->exp_min_alloc_size || n == 0)
+		return n;
+
+	/* Round up to power of two. */
+	ret = alloc->exp_min_alloc_size;
+	while (ret < n) {
+		size_t ret_old = ret;
+		ret *= 2;
+		if (ret <= ret_old)
+			ret = n;
+	}
+
+	return ret;
+}
+
+int (extract_malloc)(extract_alloc_t *alloc, void **pptr, size_t size)
+{
+	void *p;
+
+	size = round_up(alloc, size);
+	p = (alloc) ? alloc->realloc_fn(alloc->realloc_state, NULL, size) : malloc(size);
+	*pptr = p;
+	if (!p && size)
+	{
+		if (alloc) errno = ENOMEM;
+		return -1;
+	}
+	if (alloc)  alloc->stats.num_malloc += 1;
+	return 0;
+}
+
+int (extract_realloc)(extract_alloc_t *alloc, void **pptr, size_t newsize)
+{
+	void *p = (alloc) ? alloc->realloc_fn(alloc->realloc_state, *pptr, newsize) : realloc(*pptr, newsize);
+	if (!p && newsize)
+	{
+		if (alloc) errno = ENOMEM;
+		return -1;
+	}
+	*pptr = p;
+	if (alloc) alloc->stats.num_realloc += 1;
+	return 0;
+}
+
+int (extract_realloc2)(extract_alloc_t *alloc, void **pptr, size_t oldsize, size_t newsize)
+{
+	/* We ignore <oldsize> if <ptr> is NULL - allows callers to not worry
+	about edge cases e.g. with strlen+1. */
+	oldsize = (*pptr) ? round_up(alloc, oldsize) : 0;
+	newsize = round_up(alloc, newsize);
+	if (newsize == oldsize) return 0;
+	return (extract_realloc)(alloc, pptr, newsize);
+}
+
+void (extract_free)(extract_alloc_t *alloc, void **pptr)
+{
+	if (alloc)
+		(void)alloc->realloc_fn(alloc->realloc_state, *pptr, 0);
+	else
+		free(*pptr);
+	*pptr = NULL;
+	if (alloc) alloc->stats.num_free += 1;
+}
+
+void extract_alloc_exp_min(extract_alloc_t *alloc, size_t size)
+{
+	alloc->exp_min_alloc_size = size;
+}