From 469bcc917fdc827b6904c329a3c7c6e8c43aabaf Mon Sep 17 00:00:00 2001
From: Peng Wu <alexepico@gmail.com>
Date: Mon, 18 Apr 2011 15:42:21 +0800
Subject: add insert/remove array item to flexible bi-gram

---
 src/storage/flexible_ngram.h | 80 +++++++++++++++++++++++++++++++++++++-------
 src/storage/ngram.cpp        |  2 +-
 2 files changed, 68 insertions(+), 14 deletions(-)

(limited to 'src/storage')

diff --git a/src/storage/flexible_ngram.h b/src/storage/flexible_ngram.h
index 3cce47d..d82bd59 100644
--- a/src/storage/flexible_ngram.h
+++ b/src/storage/flexible_ngram.h
@@ -108,6 +108,70 @@ public:
         return true;
     }
 
+    /* insert array item */
+    bool insert_array_item(/* in */ phrase_token_t token,
+                           /* in */ const ArrayItem & item){
+        ArrayItemWithToken * begin = (ArrayItemWithToken *)
+            ((const char *)(m_chunk.begin()) + sizeof(ArrayHeader));
+        ArrayItemWithToken * end = (ArrayItemWithToken *)
+            m_chunk.end();
+
+        ArrayItemWithToken compare_item;
+        compare_item.m_token = token;
+        ArrayItemWithToken * cur_item = std_lite::lower_bound
+            (begin, end, compare_item, token_less_than);
+
+        ArrayItemWithToken insert_item;
+        insert_item.m_token = token;
+        insert_item.m_item = item;
+
+        for ( ; cur_item != end; ++cur_item ){
+            if ( cur_item->m_token > token ){
+                size_t offset = sizeof(ArrayHeader) +
+                    sizeof(ArrayItemWithToken) * (cur_item - begin);
+                m_chunk.insert_content(offset, &insert_item,
+                                       sizeof(ArrayItemWithToken));
+                return true;
+            }
+            if ( cur_item->m_token == token ){
+                return false;
+            }
+        }
+        m_chunk.insert_content(m_chunk.size(), &insert_item,
+                               sizeof(ArrayItemWithToken));
+        return true;
+    }
+
+    bool remove_array_item(/* in */ phrase_token_t token,
+                           /* out */ ArrayItem & item)
+    {
+        /* clear retval */
+        memset(&item, 0, sizeof(ArrayItem));
+
+        const ArrayItemWithToken * begin = (const ArrayItemWithToken *)
+            ((const char *)(m_chunk.begin()) + sizeof(ArrayHeader));
+        const ArrayItemWithToken * end = (const ArrayItemWithToken *)
+            m_chunk.end();
+
+        ArrayItemWithToken compare_item;
+        compare_item.m_token = token;
+        const ArrayItemWithToken * cur_item = std_lite::lower_bound
+            (begin, end, compare_item, token_less_than);
+
+        for ( ; cur_item != end; ++cur_item){
+            if ( cur_item->m_token > token )
+                return false;
+            if ( cur_item->m_token == token ){
+                memcpy(&item, &(cur_item->m_item), sizeof(ArrayItem));
+                size_t offset = sizeof(ArrayHeader) +
+                    sizeof(ArrayItemWithToken) * (cur_item - begin);
+                m_chunk.remove_content(offset, sizeof(ArrayItemWithToken));
+                return true;
+            }
+        }
+        return false;
+    }
+
     /* get array item */
     bool get_array_item(/* in */ phrase_token_t token,
                         /* out */ ArrayItem & item)
@@ -149,26 +213,16 @@ public:
         ArrayItemWithToken * cur_item = std_lite::lower_bound
             (begin, end, compare_item, token_less_than);
 
-        ArrayItemWithToken insert_item;
-        insert_item.m_token = token;
-        insert_item.m_item = item;
-
         for ( ; cur_item != end; ++cur_item ){
             if ( cur_item->m_token > token ){
-                size_t offset = sizeof(ArrayHeader) +
-                    sizeof(ArrayItemWithToken) * (cur_item - begin);
-                m_chunk.insert_content(offset, &insert_item,
-                                       sizeof(ArrayItemWithToken));
-                return true;
+                return false;
             }
             if ( cur_item->m_token == token ){
-                cur_item->m_item = item;
+                memcpy(&(cur_item->m_item), &item, sizeof(ArrayItem));
                 return true;
             }
         }
-        m_chunk.insert_content(m_chunk.size(), &insert_item,
-                               sizeof(ArrayItemWithToken));
-        return true;
+        return false;
     }
 
     /* get array header */
diff --git a/src/storage/ngram.cpp b/src/storage/ngram.cpp
index 664ecb6..e836ee5 100644
--- a/src/storage/ngram.cpp
+++ b/src/storage/ngram.cpp
@@ -73,7 +73,7 @@ bool SingleGram::prune(){
 	return true;
 }
 
-bool token_less_than(const SingleGramItem & lhs,const SingleGramItem & rhs){
+static bool token_less_than(const SingleGramItem & lhs,const SingleGramItem & rhs){
     return lhs.m_token < rhs.m_token;
 }
 
-- 
cgit