1 files changed, 247 insertions, 0 deletions
diff --git a/lib/dpkg/varbuf.c b/lib/dpkg/varbuf.c
new file mode 100644
index 0000000..c4e61e2
--- /dev/null
+++ b/lib/dpkg/varbuf.c
@@ -0,0 +1,247 @@
+/*
+ * libdpkg - Debian packaging suite library routines
+ * varbuf.c - variable length expandable buffer handling
+ *
+ * Copyright © 1994,1995 Ian Jackson <ijackson@chiark.greenend.org.uk>
+ * Copyright © 2008-2015 Guillem Jover <guillem@debian.org>
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <compat.h>
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <dpkg/i18n.h>
+#include <dpkg/dpkg.h>
+#include <dpkg/dpkg-db.h>
+
+void
+varbuf_add_char(struct varbuf *v, int c)
+{
+  varbuf_grow(v, 1);
+  v->buf[v->used++]= c;
+}
+
+void
+varbuf_dup_char(struct varbuf *v, int c, size_t n)
+{
+  if (n == 0)
+    return;
+  varbuf_grow(v, n);
+  memset(v->buf + v->used, c, n);
+  v->used += n;
+}
+
+void
+varbuf_map_char(struct varbuf *v, int c_src, int c_dst)
+{
+  size_t i;
+
+  for (i = 0; i < v->used; i++)
+    if (v->buf[i] == c_src)
+      v->buf[i] = c_dst;
+}
+
+int
+varbuf_printf(struct varbuf *v, const char *fmt, ...)
+{
+  int r;
+  va_list args;
+
+  va_start(args, fmt);
+  r = varbuf_vprintf(v, fmt, args);
+  va_end(args);
+
+  return r;
+}
+
+int
+varbuf_vprintf(struct varbuf *v, const char *fmt, va_list args)
+{
+  va_list args_copy;
+  int needed, r;
+
+  va_copy(args_copy, args);
+  needed = vsnprintf(NULL, 0, fmt, args_copy);
+  va_end(args_copy);
+
+  if (needed < 0)
+    ohshite(_("error formatting string into varbuf variable"));
+
+  varbuf_grow(v, needed + 1);
+
+  r = vsnprintf(v->buf + v->used, needed + 1, fmt, args);
+  if (r < 0)
+    ohshite(_("error formatting string into varbuf variable"));
+
+  v->used += r;
+
+  return r;
+}
+
+void
+varbuf_add_buf(struct varbuf *v, const void *s, size_t size)
+{
+  if (size == 0)
+    return;
+  varbuf_grow(v, size);
+  memcpy(v->buf + v->used, s, size);
+  v->used += size;
+}
+
+void
+varbuf_add_dir(struct varbuf *v, const char *dirname)
+{
+  varbuf_add_str(v, dirname);
+  if (v->used == 0 || v->buf[v->used - 1] != '/')
+    varbuf_add_char(v, '/');
+}
+
+void
+varbuf_end_str(struct varbuf *v)
+{
+  varbuf_grow(v, 1);
+  v->buf[v->used] = '\0';
+}
+
+const char *
+varbuf_get_str(struct varbuf *v)
+{
+  varbuf_end_str(v);
+
+  return v->buf;
+}
+
+struct varbuf *
+varbuf_new(size_t size)
+{
+  struct varbuf *v;
+
+  v = m_malloc(sizeof(*v));
+  varbuf_init(v, size);
+
+  return v;
+}
+
+void
+varbuf_init(struct varbuf *v, size_t size)
+{
+  v->used = 0;
+  v->size = size;
+  if (size)
+    v->buf = m_malloc(size);
+  else
+    v->buf = NULL;
+}
+
+void
+varbuf_reset(struct varbuf *v)
+{
+  v->used= 0;
+}
+
+void
+varbuf_grow(struct varbuf *v, size_t need_size)
+{
+  size_t new_size;
+
+  /* Make sure the varbuf is in a sane state. */
+  if (v->size < v->used)
+    internerr("varbuf used(%zu) > size(%zu)", v->used, v->size);
+
+  /* Check if we already have enough room. */
+  if ((v->size - v->used) >= need_size)
+    return;
+
+  /* Check if we overflow. */
+  new_size = (v->size + need_size) * 2;
+  if (new_size < v->size)
+    ohshit(_("cannot grow varbuf to size %zu; it would overflow"), need_size);
+
+  v->size = new_size;
+  v->buf = m_realloc(v->buf, v->size);
+}
+
+void
+varbuf_trunc(struct varbuf *v, size_t used_size)
+{
+  /* Make sure the caller does not claim more than available. */
+  if (v->size < used_size)
+    internerr("varbuf new_used(%zu) > size(%zu)", used_size, v->size);
+
+  v->used = used_size;
+}
+
+void
+varbuf_snapshot(struct varbuf *v, struct varbuf_state *vs)
+{
+  vs->v = v;
+  vs->used = v->used;
+}
+
+void
+varbuf_rollback(struct varbuf_state *vs)
+{
+  varbuf_trunc(vs->v, vs->used);
+}
+
+size_t
+varbuf_rollback_len(struct varbuf_state *vs)
+{
+  if (vs->used > vs->v->used)
+    internerr("varbuf state_used(%zu) > used(%zu)", vs->used, vs->v->used);
+  return vs->v->used - vs->used;
+}
+
+const char *
+varbuf_rollback_start(struct varbuf_state *vs)
+{
+  if (vs->v->buf == NULL) {
+    if (vs->used)
+      internerr("varbuf buf(NULL) state_used(%zu) > 0", vs->used);
+    /* XXX: Ideally this would be handled by varbuf always having a valid
+     * buf or switching all users to the getter, but for now this will do. */
+    return "";
+  }
+  return vs->v->buf + vs->used;
+}
+
+char *
+varbuf_detach(struct varbuf *v)
+{
+  char *buf = v->buf;
+
+  v->buf = NULL;
+  v->size = 0;
+  v->used = 0;
+
+  return buf;
+}
+
+void
+varbuf_destroy(struct varbuf *v)
+{
+  free(v->buf); v->buf=NULL; v->size=0; v->used=0;
+}
+
+void
+varbuf_free(struct varbuf *v)
+{
+  free(v->buf);
+  free(v);
+}