uniq_skiplist support bidirection

src/common_blocked_queue.c

@@ -13,7 +13,7 @@ int common_blocked_queue_init_ex(struct common_blocked_queue *queue,
 {
 	int result;
 
-	if ((result=init_pthread_lock(&(queue->lock))) != 0)
+	if ((result=init_pthread_lock(&queue->lock)) != 0)
 	{
 		logError("file: "__FILE__", line: %d, "
 			"init_pthread_lock fail, errno: %d, error info: %s",
@@ -21,8 +21,7 @@ int common_blocked_queue_init_ex(struct common_blocked_queue *queue,
 		return result;
 	}
 
-    result = pthread_cond_init(&(queue->cond), NULL);
-    if (result != 0)
+    if ((result=pthread_cond_init(&queue->cond, NULL)) != 0)
     {
         logError("file: "__FILE__", line: %d, "
                 "pthread_cond_init fail, "

src/shared_func.c

@@ -3092,3 +3092,13 @@ int fc_init_buffer(BufferInfo *buffer, const int buffer_size)
     buffer->length = 0;
     return 0;
 }
+
+void fc_free_buffer(BufferInfo *buffer)
+{
+    if (buffer->buff != NULL)
+    {
+        free(buffer->buff);
+        buffer->buff = NULL;
+        buffer->alloc_size = buffer->length = 0;
+    }
+}

src/shared_func.h

@@ -945,6 +945,13 @@ int fc_ceil_prime(const int n);
 */
 int fc_init_buffer(BufferInfo *buffer, const int buffer_size);
 
+/** free buffer
+ *  parameters:
+ *      buffer: the buffer to free
+ *  return: none
+*/
+void fc_free_buffer(BufferInfo *buffer);
+
 #ifdef __cplusplus
 }
 #endif

src/tests/test_uniq_skiplist.c

@@ -43,8 +43,8 @@ void set_rand_numbers(const int multiple)
     }
 
     for (i=0; i<COUNT; i++) {
-        index1 = LAST_INDEX * (int64_t)rand() / (int64_t)RAND_MAX;
-        index2 = LAST_INDEX * (int64_t)rand() / (int64_t)RAND_MAX;
+        index1 = (LAST_INDEX * (int64_t)rand()) / (int64_t)RAND_MAX;
+        index2 = (LAST_INDEX * (int64_t)rand()) / (int64_t)RAND_MAX;
         if (index1 == index2) {
             continue;
         }
@@ -140,6 +140,7 @@ static void test_find_range()
     int n_end;
     int result;
     int i;
+    int count;
     int *value;
     UniqSkiplistIterator iterator;
 
@@ -157,15 +158,63 @@ static void test_find_range()
     result = uniq_skiplist_find_range(sl, &n_start, &n_end, &iterator);
     assert(result == EINVAL);
 
+    n_start = -100;
+    n_end = -1;
+    result = uniq_skiplist_find_range(sl, &n_start, &n_end, &iterator);
+    assert(result == ENOENT);
+
     n_start = -1;
     n_end = 0;
     result = uniq_skiplist_find_range(sl, &n_start, &n_end, &iterator);
     assert(result == ENOENT);
 
     n_start = 0;
-    n_end = 10;
+    n_end = 0;
+    result = uniq_skiplist_find_range(sl, &n_start, &n_end, &iterator);
+    assert(result == ENOENT);
+
+    n_start = 2 * COUNT;
+    n_end = 2 * COUNT;
+    result = uniq_skiplist_find_range(sl, &n_start, &n_end, &iterator);
+    assert(result == ENOENT);
+    count = uniq_skiplist_iterator_count(&iterator);
+    assert(count == 0);
+
+    n_start = 2 * COUNT;
+    n_end = 4 * COUNT;
+    result = uniq_skiplist_find_range(sl, &n_start, &n_end, &iterator);
+    assert(result == ENOENT);
+    count = uniq_skiplist_iterator_count(&iterator);
+    assert(count == 0);
+
+    n_start = -100;
+    n_end = 2;
     result = uniq_skiplist_find_range(sl, &n_start, &n_end, &iterator);
     assert(result == 0);
+    count = uniq_skiplist_iterator_count(&iterator);
+    if (n_end % 2 == 0) {
+        assert(count == n_end / 2);
+    } else {
+        assert(count == n_end / 2 + 1);
+    }
+
+    n_start = 0;
+    n_end = COUNT;
+    result = uniq_skiplist_find_range(sl, &n_start, &n_end, &iterator);
+    count = uniq_skiplist_iterator_count(&iterator);
+    assert(count == (n_end - n_start) / 2);
+
+    n_start = COUNT;
+    n_end = 2 * COUNT;
+    result = uniq_skiplist_find_range(sl, &n_start, &n_end, &iterator);
+    count = uniq_skiplist_iterator_count(&iterator);
+    assert(count == (n_end - n_start) / 2);
+
+    n_start = 100;
+    n_end = 152;
+    result = uniq_skiplist_find_range(sl, &n_start, &n_end, &iterator);
+    count = uniq_skiplist_iterator_count(&iterator);
+    assert(count == (n_end - n_start) / 2);
 
     i = 0;
     while ((value=(int *)uniq_skiplist_next(&iterator)) != NULL) {
@@ -175,6 +224,23 @@ static void test_find_range()
     printf("count: %d\n\n", i);
 }
 
+static void test_reverse_iterator()
+{
+    UniqSkiplistNode *node;
+    int v;
+    int *value;
+
+    v = 21;
+    node = uniq_skiplist_find_ge_node(sl, &v);
+    if (node != NULL) {
+        while (node != sl->top) {
+            value = (int *)node->data;
+            printf("value: %d\n", *value);
+            node = (UniqSkiplistNode *)LEVEL0_DOUBLE_CHAIN_PREV_LINK(node);
+        }
+    }
+}
+
 int main(int argc, char *argv[])
 {
     int result;
@@ -189,7 +255,7 @@ int main(int argc, char *argv[])
 
     fast_mblock_manager_init();
     result = uniq_skiplist_init_ex(&factory, LEVEL_COUNT, compare_func,
-            free_test_func, 0, MIN_ALLOC_ONCE, 0);
+            free_test_func, 0, MIN_ALLOC_ONCE, 0, true);
     if (result != 0) {
         return result;
     }
@@ -209,6 +275,8 @@ int main(int argc, char *argv[])
 
     test_find_range();
 
+    test_reverse_iterator();
+
     test_delete();
     printf("\n");
 

src/uniq_skiplist.c

@@ -13,7 +13,6 @@
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
-#include <assert.h>
 #include "logger.h"
 #include "uniq_skiplist.h"
 
@@ -46,12 +45,14 @@ static void init_best_element_counts()
 int uniq_skiplist_init_ex(UniqSkiplistFactory *factory,
         const int max_level_count, skiplist_compare_func compare_func,
         uniq_skiplist_free_func free_func, const int alloc_skiplist_once,
-        const int min_alloc_elements_once, const int delay_free_seconds)
+        const int min_alloc_elements_once, const int delay_free_seconds,
+        const bool bidirection)
 {
     char name[64];
     int bytes;
     int element_size;
     int i;
+    int extra_links_count;
     int alloc_elements_once;
     int result;
 
@@ -91,10 +92,11 @@ int uniq_skiplist_init_ex(UniqSkiplistFactory *factory,
         alloc_elements_once = 1024;
     }
 
+    extra_links_count = bidirection ? 1 : 0;
     for (i=max_level_count-1; i>=0; i--) {
         sprintf(name, "sl-level%02d", i);
         element_size = sizeof(UniqSkiplistNode) +
-            sizeof(UniqSkiplistNode *) * (i + 1);
+            sizeof(UniqSkiplistNode *) * (i + 1 + extra_links_count);
         if ((result=fast_mblock_init_ex1(factory->node_allocators + i,
             name, element_size, alloc_elements_once, NULL, NULL, false)) != 0)
         {
@@ -120,6 +122,7 @@ int uniq_skiplist_init_ex(UniqSkiplistFactory *factory,
     }
     memset(factory->tail, 0, factory->node_allocators[0].info.element_size);
 
+    factory->bidirection = bidirection;
     factory->max_level_count = max_level_count;
     factory->compare_func = compare_func;
     factory->free_func = free_func;
@@ -186,6 +189,10 @@ UniqSkiplist *uniq_skiplist_new(UniqSkiplistFactory *factory,
         return NULL;
     }
     memset(sl->top, 0, top_mblock->info.element_size);
+    sl->top->level_index = sl->top_level_index;
+    if (sl->factory->bidirection) {
+        LEVEL0_DOUBLE_CHAIN_TAIL(sl) = sl->top;
+    }
 
     for (i=0; i<level_count; i++) {
         sl->top->links[i] = sl->factory->tail;
@@ -214,6 +221,7 @@ static int uniq_skiplist_grow(UniqSkiplist *sl)
         return ENOMEM;
     }
     memset(top, 0, top_mblock->info.element_size);
+    top->level_index = top_level_index;
 
     top->links[top_level_index] = sl->factory->tail;
     for (i=0; i<=sl->top_level_index; i++) {
@@ -227,6 +235,11 @@ static int uniq_skiplist_grow(UniqSkiplist *sl)
     compile_barrier();
     sl->top_level_index = top_level_index;
 
+    if (sl->factory->bidirection) {
+        LEVEL0_DOUBLE_CHAIN_TAIL(sl) =
+            LEVEL0_DOUBLE_CHAIN_PREV_LINK(old_top);
+    }
+
     UNIQ_SKIPLIST_FREE_MBLOCK_OBJECT(sl, old_top_level_index, old_top);
     return 0;
 }
@@ -332,6 +345,14 @@ int uniq_skiplist_insert(UniqSkiplist *sl, void *data)
     compile_barrier();
 
     //thread safe for one write with many read model
+    if (sl->factory->bidirection) {
+        LEVEL0_DOUBLE_CHAIN_PREV_LINK(node) = tmp_previous[0];
+        if (tmp_previous[0]->links[0] == sl->factory->tail) {
+            LEVEL0_DOUBLE_CHAIN_TAIL(sl) = node;
+        } else {
+            LEVEL0_DOUBLE_CHAIN_PREV_LINK(tmp_previous[0]->links[0]) = node;
+        }
+    }
     for (i=0; i<=level_index; i++) {
         node->links[i] = tmp_previous[i]->links[i];
         tmp_previous[i]->links[i] = node;
@@ -441,10 +462,19 @@ int uniq_skiplist_delete(UniqSkiplist *sl, void *data)
             previous = previous->links[i];
         }
 
-        assert(previous->links[i] == deleted);
         previous->links[i] = previous->links[i]->links[i];
     }
 
+    if (sl->factory->bidirection) {
+        if (deleted->links[0] == sl->factory->tail) {
+            LEVEL0_DOUBLE_CHAIN_TAIL(sl) =
+                LEVEL0_DOUBLE_CHAIN_PREV_LINK(deleted);
+        } else {
+            LEVEL0_DOUBLE_CHAIN_PREV_LINK(deleted->links[0]) =
+                LEVEL0_DOUBLE_CHAIN_PREV_LINK(deleted);
+        }
+    }
+
     if (sl->factory->free_func != NULL) {
         sl->factory->free_func(deleted->data,
                 sl->factory->delay_free_seconds);
@@ -482,7 +512,7 @@ int uniq_skiplist_find_all(UniqSkiplist *sl, void *data,
     return 0;
 }
 
-void *uniq_skiplist_find_ge(UniqSkiplist *sl, void *data)
+UniqSkiplistNode *uniq_skiplist_find_ge_node(UniqSkiplist *sl, void *data)
 {
     UniqSkiplistNode *node;
     node = uniq_skiplist_get_first_larger_or_equal(sl, data);
@@ -490,7 +520,7 @@ void *uniq_skiplist_find_ge(UniqSkiplist *sl, void *data)
         return NULL;
     }
 
-    return node->data;
+    return node;
 }
 
 int uniq_skiplist_find_range(UniqSkiplist *sl, void *start_data,

src/uniq_skiplist.h

@@ -31,6 +31,7 @@ typedef struct uniq_skiplist_factory
 {
     int max_level_count;
     int delay_free_seconds;
+    bool bidirection;       //if need reverse iteration for level 0
     skiplist_compare_func compare_func;
     uniq_skiplist_free_func free_func;
     UniqSkiplistNode *tail;  //the tail node for interator
@@ -43,7 +44,7 @@ typedef struct uniq_skiplist
     UniqSkiplistFactory *factory;
     int top_level_index;
     int element_count;
-    UniqSkiplistNode *top;   //the top node
+    UniqSkiplistNode *top;  //the top node
 } UniqSkiplist;
 
 typedef struct uniq_skiplist_iterator {
@@ -60,12 +61,13 @@ extern "C" {
 #define uniq_skiplist_init(factory, max_level_count, compare_func, free_func) \
     uniq_skiplist_init_ex(factory, max_level_count,  \
             compare_func, free_func, 64 * 1024, \
-            SKIPLIST_DEFAULT_MIN_ALLOC_ELEMENTS_ONCE, 0)
+            SKIPLIST_DEFAULT_MIN_ALLOC_ELEMENTS_ONCE, 0, false)
 
 int uniq_skiplist_init_ex(UniqSkiplistFactory *factory,
         const int max_level_count, skiplist_compare_func compare_func,
         uniq_skiplist_free_func free_func, const int alloc_skiplist_once,
-        const int min_alloc_elements_once, const int delay_free_seconds);
+        const int min_alloc_elements_once, const int delay_free_seconds,
+        const bool bidirection);
 
 void uniq_skiplist_destroy(UniqSkiplistFactory *factory);
 
@@ -81,7 +83,19 @@ int uniq_skiplist_find_all(UniqSkiplist *sl, void *data,
         UniqSkiplistIterator *iterator);
 int uniq_skiplist_find_range(UniqSkiplist *sl, void *start_data,
         void *end_data, UniqSkiplistIterator *iterator);
-void *uniq_skiplist_find_ge(UniqSkiplist *sl, void *data);
+
+UniqSkiplistNode *uniq_skiplist_find_ge_node(UniqSkiplist *sl, void *data);
+
+static inline void *uniq_skiplist_find_ge(UniqSkiplist *sl, void *data)
+{
+    UniqSkiplistNode *node;
+    node = uniq_skiplist_find_ge_node(sl, data);
+    if (node == NULL) {
+        return NULL;
+    }
+
+    return node->data;
+}
 
 static inline void uniq_skiplist_iterator(UniqSkiplist *sl,
         UniqSkiplistIterator *iterator)
@@ -103,11 +117,38 @@ static inline void *uniq_skiplist_next(UniqSkiplistIterator *iterator)
     return data;
 }
 
+static inline int uniq_skiplist_iterator_count(UniqSkiplistIterator *iterator)
+{
+    volatile UniqSkiplistNode *current;
+    int count;
+
+    count = 0;
+    current = iterator->current;
+    while (current != iterator->tail) {
+        ++count;
+        current = current->links[0];
+    }
+
+    return count;
+}
+
+static inline void *uniq_skiplist_get_first(UniqSkiplist *sl)
+{
+    if (sl->top->links[0] != sl->factory->tail) {
+        return sl->top->links[0]->data;
+    } else {
+        return NULL;
+    }
+}
+
 static inline bool uniq_skiplist_empty(UniqSkiplist *sl)
 {
     return sl->top->links[0] == sl->factory->tail;
 }
 
+#define LEVEL0_DOUBLE_CHAIN_PREV_LINK(node) node->links[node->level_index + 1]
+#define LEVEL0_DOUBLE_CHAIN_TAIL(sl)  LEVEL0_DOUBLE_CHAIN_PREV_LINK(sl->top)
+
 #ifdef __cplusplus
 }
 #endif