Add cancellation to iterators over avltree(n) and genset(dyn)

7 files changed, 83 insertions, 26 deletions

diff --git a/src/libdatastruct/avlnode_delete.c b/src/libdatastruct/avlnode_delete.c
index b0f9dd0..fffb212 100644
--- a/src/libdatastruct/avlnode_delete.c
+++ b/src/libdatastruct/avlnode_delete.c
@@ -4,7 +4,7 @@
 #include <skalibs/avlnode.h>
 #include "avlnode-internal.h"
 
-unsigned int avlnode_delete (avlnode_ref s, unsigned int max, unsigned int *root, void const *k, dtokfunc_t_ref dtok, cmpfunc_t_ref f, void *p)
+unsigned int avlnode_delete (avlnode *s, unsigned int max, unsigned int *root, void const *k, dtokfunc_t_ref dtok, cmpfunc_t_ref f, void *p)
 {
   unsigned int stack[AVLNODE_MAXDEPTH] ;
   int spin[AVLNODE_MAXDEPTH] ;
diff --git a/src/libdatastruct/avlnode_iter.c b/src/libdatastruct/avlnode_iter.c
index c6064f3..e1b17de 100644
--- a/src/libdatastruct/avlnode_iter.c
+++ b/src/libdatastruct/avlnode_iter.c
@@ -4,23 +4,27 @@
 
 struct avlnode_iter_s
 {
-  avlnode *s ;
+  avlnode const *s ;
   unsigned int max ;
+  unsigned int cut ;
   avliterfunc_t_ref f ;
   void *p ;
 } ;
 
-static int avlnode_iter_rec (struct avlnode_iter_s const *blah, unsigned int r, unsigned int h)
+static unsigned int avlnode_iter_rec (struct avlnode_iter_s const *blah, unsigned int r, unsigned int h)
 {
-  return (r < blah->max) ?
-    avlnode_iter_rec(blah, blah->s[r].child[0], h+1)
-    && (*blah->f)(blah->s[r].data, h, blah->p)
-    && avlnode_iter_rec(blah, blah->s[r].child[1], h+1)
-   : 1 ;
+  if (r >= blah->max) return blah->max ;
+  {
+    unsigned int res = avlnode_iter_rec(blah, blah->s[r].child[0], h+1) ;
+    if (res != blah->max) return res ;
+  }
+  if (r == blah->cut) return blah->max ;
+  if (!(*blah->f)(blah->s[r].data, h, blah->p)) return r ;
+  return avlnode_iter_rec(blah, blah->s[r].child[1], h+1) ;
 }
 
-int avlnode_iter (avlnode *s, unsigned int max, unsigned int r, avliterfunc_t_ref f, void *p)
+unsigned int avlnode_iter_nocancel (avlnode *s, unsigned int max, unsigned int cut, unsigned int r, avliterfunc_t_ref f, void *p)
 {
-  struct avlnode_iter_s blah = { s, max, f, p } ;
+  struct avlnode_iter_s blah = { .s = s, .max = max, .cut = cut, .f = f, .p = p } ;
   return avlnode_iter_rec(&blah, r, 0) ;
 }
diff --git a/src/libdatastruct/avlnode_iter_withcancel.c b/src/libdatastruct/avlnode_iter_withcancel.c
new file mode 100644
index 0000000..44ba12e
--- /dev/null
+++ b/src/libdatastruct/avlnode_iter_withcancel.c
@@ -0,0 +1,17 @@
+/* ISC license. */
+
+#include <errno.h>
+#include <skalibs/avlnode.h>
+
+int avlnode_iter_withcancel (avlnode *tree, unsigned int max, unsigned int root, avliterfunc_t_ref f, avliterfunc_t_ref cancelf, void *stuff)
+{
+  unsigned int cut = avlnode_iter_nocancel(tree, max, max, root, f, stuff) ;
+  if (cut != max)
+  {
+    int e = errno ;
+    avlnode_iter_nocancel(tree, max, cut, root, cancelf, stuff) ;
+    errno = e ;
+    return 0 ;
+  }
+  return 1 ;
+}
diff --git a/src/libdatastruct/genset_iter.c b/src/libdatastruct/genset_iter.c
index fba95de..f78945d 100644
--- a/src/libdatastruct/genset_iter.c
+++ b/src/libdatastruct/genset_iter.c
@@ -4,16 +4,16 @@
 #include <skalibs/functypes.h>
 #include <skalibs/genset.h>
 
-unsigned int genset_iter (genset *g, iterfunc_t_ref f, void *stuff)
+unsigned int genset_iter_nocancel (genset *g, unsigned int n, iterfunc_t_ref f, void *stuff)
 {
-  unsigned char bits[bitarray_div8(g->max)] ;
-  unsigned int i = 0, j = 0, n = 0, m = genset_n(g) ;
-  bitarray_setn(bits, 0, g->max) ;
-  for (; i < g->sp ; i++) bitarray_clear(bits, g->freelist[i]) ;
-  for (i = 0 ; (i < g->max) && (j < m) ; i++) if (bitarray_peek(bits, i))
+  unsigned char bits[bitarray_div8(n)] ;
+  unsigned int i = 0, j = 0, m = genset_n(g) ;
+  bitarray_setn(bits, 0, n) ;
+  for (; i < g->sp ; i++) if (g->freelist[i] < n) bitarray_clear(bits, g->freelist[i]) ;
+  for (i = 0 ; (i < n) && (j < m) ; i++) if (bitarray_peek(bits, i))
   {
     j++ ;
-    if ((*f)(g->storage + i * g->esize, stuff)) n++ ;
+    if (!(*f)(g->storage + i * g->esize, stuff)) break ;
   }
-  return n ;
+  return i ;
 }
diff --git a/src/libdatastruct/genset_iter_withcancel.c b/src/libdatastruct/genset_iter_withcancel.c
new file mode 100644
index 0000000..fa8074b
--- /dev/null
+++ b/src/libdatastruct/genset_iter_withcancel.c
@@ -0,0 +1,18 @@
+/* ISC license. */
+
+#include <errno.h>
+#include <skalibs/functypes.h>
+#include <skalibs/genset.h>
+
+int genset_iter_withcancel (genset *g, iterfunc_t_ref f, iterfunc_t_ref cancelf, void *stuff)
+{
+  unsigned int n = genset_iter(g, f, stuff) ;
+  if (n < g->max)
+  {
+    int e = errno ;
+    genset_iter_nocancel(g, n, cancelf, stuff) ;
+    errno = e ;
+    return 0 ;
+  }
+  return 1 ;
+}
diff --git a/src/libdatastruct/gensetdyn_iter.c b/src/libdatastruct/gensetdyn_iter.c
index 51d598b..586aa11 100644
--- a/src/libdatastruct/gensetdyn_iter.c
+++ b/src/libdatastruct/gensetdyn_iter.c
@@ -4,23 +4,23 @@
 #include <skalibs/functypes.h>
 #include <skalibs/gensetdyn.h>
 
-unsigned int gensetdyn_iter (gensetdyn *g, iterfunc_t_ref f, void *stuff)
+unsigned int gensetdyn_iter_nocancel (gensetdyn *g, unsigned int n, iterfunc_t_ref f, void *stuff)
 {
  /*
     XXX: we may be called by a freeing function, so we cannot alloc -
     XXX: so pray that the bitarray fits in the stack.
  */
-  unsigned char bits[bitarray_div8(g->storage.len)] ;
-  unsigned int i = 0, j = 0, n = 0, m = gensetdyn_n(g) ;
+  unsigned char bits[bitarray_div8(n)] ;
+  unsigned int i = 0, j = 0, m = gensetdyn_n(g) ;
   register unsigned int *fl = genalloc_s(unsigned int, &g->freelist) ;
   register unsigned int sp = genalloc_len(unsigned int, &g->freelist) ;
-  bitarray_setn(bits, 0, g->storage.len) ;
+  bitarray_setn(bits, 0, n) ;
   
-  for (; i < sp ; i++) bitarray_clear(bits, fl[i]) ;
-  for (i = 0 ; (i < g->storage.len) && (j < m) ; i++) if (bitarray_peek(bits, i))
+  for (; i < sp ; i++) if (fl[i] < n) bitarray_clear(bits, fl[i]) ;
+  for (i = 0 ; (i < n) && (j < m) ; i++) if (bitarray_peek(bits, i))
   {
     j++ ;
-    if ((*f)(gensetdyn_p(g, i), stuff)) n++ ;
+    if (!(*f)(gensetdyn_p(g, i), stuff)) break ;
   }
-  return n ;
+  return i ;
 }
diff --git a/src/libdatastruct/gensetdyn_iter_withcancel.c b/src/libdatastruct/gensetdyn_iter_withcancel.c
new file mode 100644
index 0000000..ffac1e0
--- /dev/null
+++ b/src/libdatastruct/gensetdyn_iter_withcancel.c
@@ -0,0 +1,18 @@
+/* ISC license. */
+
+#include <errno.h>
+#include <skalibs/functypes.h>
+#include <skalibs/gensetdyn.h>
+
+int gensetdyn_iter_withcancel (gensetdyn *g, iterfunc_t_ref f, iterfunc_t_ref cancelf, void *stuff)
+{
+  unsigned int n = gensetdyn_iter(g, f, stuff) ;
+  if (n < g->storage.len)
+  {
+    int e = errno ;
+    gensetdyn_iter_nocancel(g, n, cancelf, stuff) ;
+    errno = e ;
+    return 0 ;
+  }
+  return 1 ;
+}