2 * Copyright (c) 1997 - 2002 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
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7 * modification, are permitted provided that the following conditions
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11 * notice, this list of conditions and the following disclaimer.
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14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the Institute nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
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34 #include "krb5_locl.h"
35 #include "store-int.h"
37 typedef struct emem_storage{
45 emem_fetch(krb5_storage *sp, void *data, size_t size)
47 emem_storage *s = (emem_storage*)sp->data;
48 if((size_t)(s->base + s->len - s->ptr) < size)
49 size = s->base + s->len - s->ptr;
50 memmove(data, s->ptr, size);
51 sp->seek(sp, size, SEEK_CUR);
56 emem_store(krb5_storage *sp, const void *data, size_t size)
58 emem_storage *s = (emem_storage*)sp->data;
59 if(size > (size_t)(s->base + s->size - s->ptr)){
62 off = s->ptr - s->base;
66 base = realloc(s->base, sz);
71 s->ptr = (unsigned char*)base + off;
73 memmove(s->ptr, data, size);
74 sp->seek(sp, size, SEEK_CUR);
79 emem_seek(krb5_storage *sp, off_t offset, int whence)
81 emem_storage *s = (emem_storage*)sp->data;
84 if((size_t)offset > s->size)
88 s->ptr = s->base + offset;
89 if((size_t)offset > s->len)
93 sp->seek(sp,s->ptr - s->base + offset, SEEK_SET);
96 sp->seek(sp, s->len + offset, SEEK_SET);
102 return s->ptr - s->base;
106 emem_trunc(krb5_storage *sp, off_t offset)
108 emem_storage *s = (emem_storage*)sp->data;
110 * If offset is larget then current size, or current size is
111 * shrunk more then half of the current size, adjust buffer.
118 } else if ((size_t)offset > s->size || (s->size / 2) > (size_t)offset) {
121 off = s->ptr - s->base;
122 base = realloc(s->base, offset);
125 if ((size_t)offset > s->size)
126 memset((char *)base + s->size, 0, offset - s->size);
129 s->ptr = (unsigned char *)base + off;
132 if ((s->ptr - s->base) > offset)
133 s->ptr = s->base + offset;
139 emem_free(krb5_storage *sp)
141 emem_storage *s = sp->data;
142 memset(s->base, 0, s->len);
147 * Create a elastic (allocating) memory storage backend. Memory is
148 * allocated on demand. Free returned krb5_storage with
149 * krb5_storage_free().
151 * @return A krb5_storage on success, or NULL on out of memory error.
153 * @ingroup krb5_storage
155 * @sa krb5_storage_from_mem()
156 * @sa krb5_storage_from_readonly_mem()
157 * @sa krb5_storage_from_fd()
158 * @sa krb5_storage_from_data()
161 KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
162 krb5_storage_emem(void)
167 sp = malloc(sizeof(krb5_storage));
171 s = malloc(sizeof(*s));
178 sp->eof_code = HEIM_ERR_EOF;
180 s->base = malloc(s->size);
181 if (s->base == NULL) {
188 sp->fetch = emem_fetch;
189 sp->store = emem_store;
190 sp->seek = emem_seek;
191 sp->trunc = emem_trunc;
192 sp->free = emem_free;
193 sp->max_alloc = UINT_MAX/8;