Added a single-linked double-ended list module. Mostly syntactic sugar.

The SLIST_WALK_DELSAFE macro has well-defined semantics of the auxilliary
variable: it's a pointer to the previous list item or to the list head,
making it possible to delete the current item efficiently by calling
slist_remove_after().

Unfortunately, I failed to write SLIST_FOR_EACH_DELSAFE, C syntax doesn't
seem to be flexible enough for that.

diff --git a/lib/Makefile b/lib/Makefile
index c785ee643274a55be247c61fbd7f62b089a361cb..bf3ede457b21cbdc7dc6a65c4e4f469b2c45adde 100644 (file)
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -9,7 +9,7 @@ endif
 LIBUCW_MODS= \
        alloc alloc_str realloc mempool mempool-str mempool-fmt \
        mmap pagecache partmap hashfunc \
-       lists sorter bitsig kmp \
+       lists slists sorter bitsig kmp \
        log log-file proctitle \
        conf ipaccess \
        profile \
@@ -76,13 +76,14 @@ $(o)/lib/redblack-test: $(o)/lib/redblack-test.o $(LIBUCW)
 $(o)/lib/binheap-test: $(o)/lib/binheap-test.o $(LIBUCW)
 $(o)/lib/lizard-test: $(o)/lib/lizard-test.o $(LIBUCW)
 
-TESTS+=$(addprefix $(o)/lib/,regex.test unicode-utf8.test hash-test.test mempool.test stkstring.test)
+TESTS+=$(addprefix $(o)/lib/,regex.test unicode-utf8.test hash-test.test mempool.test stkstring.test slists.test)
 $(o)/lib/regex.test: $(o)/lib/regex-t
 $(o)/lib/unicode-utf8.test: $(o)/lib/unicode-utf8-t
 $(o)/lib/hash-test.test: $(o)/lib/hash-test
 $(o)/lib/mempool.test: $(o)/lib/mempool-fmt-t $(o)/lib/mempool-str-t
 $(o)/lib/stkstring.test: $(o)/lib/stkstring-t
 $(o)/lib/bitops.test: $(o)/lib/bit-ffs-t $(o)/lib/bit-fls-t
+$(o)/lib/slists.test: $(o)/lib/slists-t
 
 INCLUDES+=$(o)/lib/.include-stamp
 $(o)/lib/.include-stamp: $(addprefix $(s)/lib/,$(LIBUCW_INCLUDES))

diff --git a/lib/slists.c b/lib/slists.c
new file mode 100644 (file)
index 0000000..fffc64e
--- /dev/null
+++ b/lib/slists.c
@@ -0,0 +1,83 @@
+/*
+ *     UCW Library -- Single-Linked Lists
+ *
+ *     (c) 2005 Martin Mares <mj@ucw.cz>
+ *
+ *     This software may be freely distributed and used according to the terms
+ *     of the GNU Lesser General Public License.
+ */
+
+#include "lib/lib.h"
+#include "lib/slists.h"
+
+static inline snode *
+slist_raw_prev(slist *l, snode *n)
+{
+  snode *m = &l->head;
+  while (m)
+    {
+      if (n == m->next)
+       return m;
+      m = m->next;
+    }
+  ASSERT(0);
+}
+
+void *
+slist_prev(slist *l, snode *n)
+{
+  snode *p = slist_raw_prev(l, n);
+  return (p == &l->head) ? NULL : p;
+}
+
+void
+slist_insert_before(slist *l, snode *what, snode *before)
+{
+  what->next = before;
+  slist_raw_prev(l, before)->next = what;
+}
+
+void
+slist_remove(slist *l, snode *n)
+{
+  snode *p = slist_raw_prev(l, n);
+  slist_remove_after(l, p);
+}
+
+#ifdef TEST
+
+#include <stdio.h>
+#include <alloca.h>
+
+int main(void)
+{
+  slist l;
+
+  struct x {
+    snode n;
+    int val;
+  };
+
+  slist_init(&l);
+  for (int i=1; i<=10; i++)
+    {
+      struct x *x = alloca(sizeof(*x));
+      x->val = i;
+      if (i % 2)
+       slist_add_head(&l, &x->n);
+      else
+       slist_add_tail(&l, &x->n);
+    }
+
+  struct x *x, *prev;
+  SLIST_WALK_DELSAFE(x, l, prev)
+    if (x->val == 5)
+      slist_remove_after(&l, &prev->n);
+    else if (x->val == 6)
+      slist_remove(&l, &x->n);
+  SLIST_FOR_EACH(struct x *, x, l)
+    printf("%d/", x->val);
+  putchar('\n');
+}
+
+#endif

diff --git a/lib/slists.h b/lib/slists.h
new file mode 100644 (file)
index 0000000..b0e9f4e
--- /dev/null
+++ b/lib/slists.h
@@ -0,0 +1,90 @@
+/*
+ *     UCW Library -- Single-Linked Lists
+ *
+ *     (c) 2005 Martin Mares <mj@ucw.cz>
+ *
+ *     This software may be freely distributed and used according to the terms
+ *     of the GNU Lesser General Public License.
+ */
+
+#ifndef _UCW_SLISTS_H
+#define _UCW_SLISTS_H
+
+typedef struct snode {
+  struct snode *next;
+} snode;
+
+typedef struct slist {
+  struct snode head, *last;
+} slist;
+
+static inline void *slist_head(slist *l)
+{
+  return l->head.next;
+}
+
+static inline void *slist_tail(slist *l)
+{
+  return l->last;
+}
+
+static inline void *slist_next(snode *n)
+{
+  return n->next;
+}
+
+static inline int slist_empty(slist *l)
+{
+  return !l->head.next;
+}
+
+#define SLIST_WALK(n,list) for(n=(void*)(list).head.next; (n); (n)=(void*)((snode*)(n))->next)
+#define SLIST_WALK_DELSAFE(n,list,prev) for((prev)=(void*)&(list).head; (n)=(void*)((snode*)prev)->next; (prev)=(((snode*)(prev))->next==(snode*)(n) ? (void*)(n) : (void*)(prev)))
+#define SLIST_FOR_EACH(type,n,list) for(type n=(void*)(list).head.next; n; n=(void*)((snode*)(n))->next)
+
+static inline void slist_insert_after(slist *l, snode *what, snode *after)
+{
+  what->next = after->next;
+  after->next = what;
+  if (!what->next)
+    l->last = what;
+}
+
+static inline void slist_add_head(slist *l, snode *n)
+{
+  n->next = l->head.next;
+  l->head.next = n;
+  if (!l->last)
+    l->last = n;
+}
+
+static inline void slist_add_tail(slist *l, snode *n)
+{
+  if (l->last)
+    l->last->next = n;
+  else
+    l->head.next = n;
+  n->next = NULL;
+  l->last = n;
+}
+
+static inline void slist_init(slist *l)
+{
+  l->head.next = l->last = NULL;
+}
+
+static inline void slist_remove_after(slist *l, snode *after)
+{
+  snode *n = after->next;
+  after->next = n->next;
+  if (l->last == n)
+    l->last = (after == &l->head) ? NULL : after;
+}
+
+/* Non-trivial functions */
+
+void *slist_prev(slist *l, snode *n);
+void slist_insert_before(slist *l, snode *what, snode *before);
+void slist_remove(slist *l, snode *n);
+
+#endif

diff --git a/lib/slists.t b/lib/slists.t
new file mode 100644 (file)
index 0000000..f18dc7a
--- /dev/null
+++ b/lib/slists.t
@@ -0,0 +1,4 @@
+# Test for slists module
+
+Run:   obj/lib/slists-t
+Out:   9/7/3/1/2/4/8/10/