From 87c1f5002150f24a45bf0b33f4fa0b7de44aaa2e Mon Sep 17 00:00:00 2001
From: Peng Wu <alexepico@gmail.com>
Date: Fri, 17 Apr 2015 14:52:57 +0800
Subject: write class FlexibleBigram in progress

---
 src/storage/flexible_ngram_kyotodb.h | 116 +++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)

(limited to 'src')

diff --git a/src/storage/flexible_ngram_kyotodb.h b/src/storage/flexible_ngram_kyotodb.h
index 9cf866b..fbbf28b 100644
--- a/src/storage/flexible_ngram_kyotodb.h
+++ b/src/storage/flexible_ngram_kyotodb.h
@@ -30,6 +30,32 @@
 
 namespace pinyin{
 
+class FlexibleKeyCollectVisitor : public DB::Visitor {
+private:
+    GArray * m_items;
+public:
+    FlexibleKeyCollectVisitor(GArray * items) {
+        m_items = items;
+    }
+
+    virtual const char* visit_full(const char* kbuf, size_t ksiz,
+                                   const char* vbuf, size_t vsiz, size_t* sp) {
+        /* skip magic header. */
+        if (ksiz != sizeof(phrase_token_t))
+            return NOP;
+
+        const phrase_token_t * token = (phrase_token_t *) kbuf;
+        g_array_append_val(m_items, *token);
+        return NOP;
+    }
+
+    virtual const char* visit_empty(const char* kbuf, size_t ksiz, size_t* sp) {
+        /* assume no empty record. */
+        assert (FALSE);
+        return NOP;
+    }
+};
+
 /**
  * FlexibleBigram:
  * @MagicHeader: the struct type of the magic header.
@@ -148,6 +174,96 @@ public:
             return true;
         return false;
     }
+
+    /**
+     * FlexibleBigram::load:
+     * @index: the previous token in the flexible bi-gram.
+     * @single_gram: the single gram of the previous token.
+     * @returns: whether the load operation is successful.
+     *
+     * Load the single gram of the previous token.
+     *
+     */
+    bool load(phrase_token_t index,
+              FlexibleSingleGram<ArrayHeader, ArrayItem> * & single_gram){
+        single_gram = NULL;
+        if ( !m_db )
+            return false;
+
+        /* Use DB interface, first check, second reserve the memory chunk,
+           third get value into the chunk. */
+        const char * kbuf = (char *) &index;
+        const int32_t vsiz = m_db->check(kbuf, sizeof(phrase_token_t));
+        /* -1 on failure. */
+        if (-1 == vsiz)
+            return false;
+
+        m_chunk.set_size(vsiz);
+        char * vbuf = (char *) m_chunk.begin();
+        assert (vsiz == m_db->get(kbuf, sizeof(phrase_token_t),
+                                  vbuf, vsiz));
+
+        single_gram = new FlexibleSingleGram<ArrayHeader, ArrayItem>
+            (m_chunk.begin(), vsiz);
+
+        return true;
+    }
+
+    /**
+     * FlexibleBigram::store:
+     * @index: the previous token in the flexible bi-gram.
+     * @single_gram: the single gram of the previous token.
+     * @returns: whether the store operation is successful.
+     *
+     * Store the single gram of the previous token.
+     *
+     */
+    bool store(phrase_token_t index,
+               FlexibleSingleGram<ArrayHeader, ArrayItem> * single_gram){
+        if ( !m_db )
+            return false;
+
+        const char * kbuf = (char *) &index;
+        char * vbuf = (char *) single_gram->m_chunk.begin();
+        size_t vsiz = single_gram->m_chunk.size();
+        return m_db->set(kbuf, sizeof(phrase_token_t), vbuf, vsiz);
+    };
+
+    /**
+     * FlexibleBigram::remove:
+     * @index: the previous token in the flexible bi-gram.
+     * @returns: whether the remove operation is successful.
+     *
+     * Remove the single gram of the previous token.
+     *
+     */
+    bool remove(phrase_token_t index){
+        if ( !m_db )
+            return false;
+
+        const char * kbuf = (char *) &index;
+        return m_db->remove(kbuf, sizeof(phrase_token_t));
+    }
+
+    /**
+     * FlexibleBigram::get_all_items:
+     * @items: the GArray to store all previous tokens.
+     * @returns: whether the get operation is successful.
+     *
+     * Get the array of all previous tokens for parameter estimation.
+     *
+     */
+    bool get_all_items(GArray * items){
+        g_array_set_size(items, 0);
+
+        if ( !m_db )
+            return false;
+
+        FlexibleKeyCollectVisitor visitor(items);
+        m_db->iterate(&visitor, false);
+
+        return true;
+    };
 };
 
 };
-- 
cgit