From 39434b7b560399eba0050024bec19aefc772b457 Mon Sep 17 00:00:00 2001
From: Peng Wu <alexepico@gmail.com>
Date: Fri, 26 Oct 2012 14:49:11 +0800
Subject: write mask out method

---
 src/storage/phrase_index.cpp | 45 +++++++++++++++++++++++++++++++++++++++++++-
 src/storage/phrase_index.h   | 27 +++++++++++++++++++++++++-
 2 files changed, 70 insertions(+), 2 deletions(-)

diff --git a/src/storage/phrase_index.cpp b/src/storage/phrase_index.cpp
index be78dfa..6a4ae7e 100644
--- a/src/storage/phrase_index.cpp
+++ b/src/storage/phrase_index.cpp
@@ -262,7 +262,7 @@ bool FacadePhraseIndex::merge_with_mask(guint8 phrase_index,
     /* check mask and value. */
     phrase_token_t index_mask = PHRASE_INDEX_LIBRARY_INDEX(mask);
     phrase_token_t index_value = PHRASE_INDEX_LIBRARY_INDEX(value);
-    if (!((index_mask & phrase_index) == index_value))
+    if ((phrase_index & index_mask) != index_value)
         return false;
 
     /* unload old sub phrase index */
@@ -606,6 +606,49 @@ bool FacadePhraseIndex::compact(){
     return true;
 }
 
+bool SubPhraseIndex::mask_out(phrase_token_t mask, phrase_token_t value){
+    PhraseIndexRange range;
+    if (ERROR_OK != get_range(range))
+        return false;
+
+    /* calculate mask and value for sub phrase index. */
+    mask &= PHRASE_MASK; value &= PHRASE_MASK;
+
+    for (phrase_token_t token = range.m_range_begin;
+         token < range.m_range_end; ++token) {
+        if ((token & mask) != value)
+            continue;
+
+        PhraseItem * item = NULL;
+        remove_phrase_item(token, item);
+        if (item)
+            delete item;
+    }
+
+    return true;
+}
+
+bool FacadePhraseIndex::mask_out(guint8 phrase_index,
+                                 phrase_token_t mask,
+                                 phrase_token_t value){
+    SubPhraseIndex * & sub_phrases = m_sub_phrase_indices[phrase_index];
+    if (!sub_phrases)
+        return false;
+
+    /* check mask and value. */
+    phrase_token_t index_mask = PHRASE_INDEX_LIBRARY_INDEX(mask);
+    phrase_token_t index_value = PHRASE_INDEX_LIBRARY_INDEX(value);
+
+    if ((phrase_index & index_mask ) != index_value)
+        return false;
+
+    m_total_freq -= sub_phrases->get_phrase_index_total_freq();
+    bool retval = sub_phrases->mask_out(mask, value);
+    m_total_freq += sub_phrases->get_phrase_index_total_freq();
+
+    return retval;
+}
+
 namespace pinyin{
 const pinyin_table_info_t pinyin_phrase_files[PHRASE_INDEX_LIBRARY_COUNT] =
     {
diff --git a/src/storage/phrase_index.h b/src/storage/phrase_index.h
index 7eb79fc..75813bf 100644
--- a/src/storage/phrase_index.h
+++ b/src/storage/phrase_index.h
@@ -420,6 +420,16 @@ public:
      */
     int remove_phrase_item(phrase_token_t token, /* out */ PhraseItem * & item);
 
+    /**
+     * SubPhraseIndex::mask_out:
+     * @mask: the mask.
+     * @value: the value.
+     * @returns: whether the mask out operation is successful.
+     *
+     * Mask out the matched phrase items.
+     *
+     */
+    bool mask_out(phrase_token_t mask, phrase_token_t value);
 };
 
 /**
@@ -557,6 +567,21 @@ public:
      */
     bool compact();
 
+    /**
+     * FacadePhraseIndex::mask_out:
+     * @phrase_index: the index of sub phrase index.
+     * @mask: the mask.
+     * @value: the value.
+     * @returns: whether the mask out operation is successful.
+     *
+     * Mask out the matched phrase items.
+     *
+     * Note: should call compact() after the mask out operation.
+     *
+     */
+    bool mask_out(guint8 phrase_index,
+                  phrase_token_t mask, phrase_token_t value);
+
     /**
      * FacadePhraseIndex::get_sub_phrase_range:
      * @min_index: the minimal sub phrase index.
@@ -823,7 +848,7 @@ extern const pinyin_table_info_t pinyin_phrase_files[PHRASE_INDEX_LIBRARY_COUNT]
 
 PhraseIndexLogger * mask_out_phrase_index_logger
 (PhraseIndexLogger * oldlogger, phrase_token_t mask, phrase_token_t value);
- 
+
 };
 
 #endif
-- 
cgit