add empty function to process the foreign key rewrite, this waits to be implemented

README.md

@@ -30,3 +30,8 @@ new features added
 + timestamp
 + show create table
 
+
+obselete functions deleted
+
++ annotation
+

main/ddl_handler.cc

@@ -11,6 +11,10 @@
 
 #include <util/yield.hpp>
 
+
+//a list of ddl handlers, buildddlhandler, and ddlexecutor
+
+//################################################################Create table handler#########################################################################################
 class CreateTableHandler : public DDLHandler {
     virtual AbstractQueryExecutor *
         rewriteAndUpdate(Analysis &a, LEX *lex, const Preamble &pre) const
@@ -75,6 +79,7 @@ class CreateTableHandler : public DDLHandler {
 	    //对现有的每个field, 如id,name, 都在内部通过createAndRewriteField函数扩展成多个洋葱+salt.
 	    //其中洋葱有多个层, 其通过newCreateField函数, 决定了类型, 而新的field的名字, 就是洋葱的名字传过去的.
             //扩展以后, 就是新的Create_field类型了, 这了返回的list是被继续传到引用参数里面的, 很奇怪的用法.
+            //key data在这里的作用是, 决定是不是unique, 从而选择和是的洋葱层次.
             new_lex->alter_info.create_list =
                 accumList<Create_field>(it,
                     [&a, &tm, &key_data] (List<Create_field> out_list,
@@ -87,6 +92,7 @@ class CreateTableHandler : public DDLHandler {
             //         Rewrite INDEX
             // -----------------------------
             highLevelRewriteKey(*tm.get(), *lex, new_lex, a);
+            highLevelRewriteForeignKey();
 
             // -----------------------------
             //         Update TABLE
@@ -128,6 +134,10 @@ class CreateTableHandler : public DDLHandler {
     }
 };
 
+
+
+
+//################################################################Alter table handler#########################################################################################
 // mysql does not support indiscriminate add-drops
 // ie,
 //      mysql> create table pk (x integer);
@@ -176,6 +186,11 @@ public:
     AlterTableHandler() : sub_dispatcher(buildAlterSubDispatcher()) {}
 };
 
+
+
+//################################################################drop table handler#########################################################################################
+
+
 class DropTableHandler : public DDLHandler {
     virtual AbstractQueryExecutor *
         rewriteAndUpdate(Analysis &a, LEX *lex, const Preamble &pre) const
@@ -219,6 +234,9 @@ class DropTableHandler : public DDLHandler {
     }
 };
 
+
+//################################################################Create db handler#########################################################################################
+
 class CreateDBHandler : public DDLHandler {
     virtual AbstractQueryExecutor *
         rewriteAndUpdate(Analysis &a, LEX *const lex, const Preamble &pre)
@@ -248,6 +266,9 @@ class CreateDBHandler : public DDLHandler {
     }
 };
 
+
+//################################################################change db handler#########################################################################################
+
 class ChangeDBHandler : public DDLHandler {
     virtual AbstractQueryExecutor *
         rewriteAndUpdate(Analysis &a, LEX *const lex, const Preamble &pre)
@@ -258,6 +279,8 @@ class ChangeDBHandler : public DDLHandler {
     }
 };
 
+
+//################################################################drop db handler#########################################################################################
 class DropDBHandler : public DDLHandler {
     virtual AbstractQueryExecutor *
         rewriteAndUpdate(Analysis &a, LEX *const lex, const Preamble &pre)
@@ -274,6 +297,8 @@ class DropDBHandler : public DDLHandler {
     }
 };
 
+
+//################################################################lock table handler#########################################################################################
 class LockTablesHandler : public DDLHandler {
     virtual AbstractQueryExecutor *
         rewriteAndUpdate(Analysis &a, LEX *const lex, const Preamble &pre)
@@ -289,6 +314,8 @@ class LockTablesHandler : public DDLHandler {
     }
 };
 
+
+//################################################################Create index handler#########################################################################################
 class CreateIndexHandler : public DDLHandler {
     virtual AbstractQueryExecutor *
         rewriteAndUpdate(Analysis &a, LEX *const lex, const Preamble &pre)
@@ -311,6 +338,7 @@ class CreateIndexHandler : public DDLHandler {
     }
 };
 
+
 static std::string
 empty_if_null(const char *const p)
 {
@@ -323,7 +351,6 @@ AbstractQueryExecutor *DDLHandler::
 transformLex(Analysis &a, LEX *lex) const
 {
 
-    std::cout<<__PRETTY_FUNCTION__<<":"<<__LINE__<<":"<<__FILE__<<":"<<__LINE__<<std::endl<<std::endl;
     assert(a.deltas.size() == 0);
 
     AssignOnce<std::string> db;
@@ -393,7 +420,6 @@ nextImpl(const ResType &res, const NextParams &nparams)
                     "deltaOutputBeforeQuery failed for DDL");
                 this->embedded_completion_id = embedded_completion_id;
             }
-            std::cout<<__PRETTY_FUNCTION__<<":"<<__LINE__<<":"<<__FILE__<<":"<<__LINE__<<std::endl;
 	    std::cout<<RED_BEGIN<<"rewritten DDL: "<<this->new_query<<COLOR_END<<std::endl;
             return CR_QUERY_AGAIN(this->new_query);
         }
@@ -402,7 +428,6 @@ nextImpl(const ResType &res, const NextParams &nparams)
         this->ddl_res = res;
 
         yield {
-            std::cout<<__PRETTY_FUNCTION__<<":"<<__LINE__<<":"<<__FILE__<<":"<<__LINE__<<std::endl<<std::endl;
             return CR_QUERY_AGAIN(
                 " INSERT INTO " + MetaData::Table::remoteQueryCompletion() +
                 "   (embedded_completion_id, completion_type) VALUES"
@@ -421,7 +446,7 @@ nextImpl(const ResType &res, const NextParams &nparams)
         TEST_ErrPkt(deltaOutputAfterQuery(nparams.ps.getEConn(), this->deltas,
                                           this->embedded_completion_id.get()),
                    "deltaOuputAfterQuery failed for DDL");
-        std::cout<<__PRETTY_FUNCTION__<<":"<<__LINE__<<":"<<__FILE__<<":"<<__LINE__<<std::endl<<std::endl;
+//        std::cout<<__PRETTY_FUNCTION__<<":"<<__LINE__<<":"<<__FILE__<<":"<<__LINE__<<std::endl<<std::endl;
         yield return CR_RESULTS(this->ddl_res.get());
     }
 

main/rewrite_util.cc

@@ -281,6 +281,7 @@ getOriginalKeyName(const Key &key)
     return out_name;
 }
 
+/*
 static std::vector<Key *>
 rewrite_key(const TableMeta &tm, const Key &key, const Analysis &a)
 {
@@ -346,6 +347,76 @@ rewrite_key(const TableMeta &tm, const Key &key, const Analysis &a)
 
     return output_keys;
 }
+*/
+
+static std::vector<Key *>
+rewrite_key1(const TableMeta &tm, const Key &key, const Analysis &a)
+{
+    std::vector<Key *> output_keys;
+
+    //从左到右分别是三种类型: oOPE, oDET, oPLAIN, 对于每个语句的index都是这样
+    //比如自己要alter table add 的index, 其对应index的名字, 以及相关的column信息
+    //比如create的时候, 产生的index, 其对应的名字以及相关的columns, 这样包含在key里面了
+    const std::vector<onion> key_onions = getOnionIndexTypes();
+    for (auto onion_it : key_onions) {
+        const onion o = onion_it;
+        THD* cthd = current_thd;
+        //原始key的拷贝
+        Key *const new_key = key.clone(cthd->mem_root);
+        //通过key的原始名字+onion+tm哈希获得新的key名字,用的是std::hash<string>算法.
+        // Set anonymous name.
+        const std::string new_name =
+            a.getAnonIndexName(tm, getOriginalKeyName(key), o);
+        //设置key的新名字, 以及新的key对应的column清空??
+        new_key->name = string_to_lex_str(new_name);
+        new_key->columns.empty();
+
+        //遍历原始的key的columns, 改写, 变成新key的colukns
+        // Set anonymous columns.
+        auto col_it =
+            RiboldMYSQL::constList_iterator<Key_part_spec>(key.columns);
+        for (;;) {
+            const Key_part_spec *const key_part = col_it++;
+            if (NULL == key_part) {
+                output_keys.push_back(new_key);
+                break;
+            }
+            //复制一个column信息
+            Key_part_spec *const new_key_part = copyWithTHD(key_part);
+            //原始的key_part, 也就是一个column, 里面取一个field_name出来
+            const std::string field_name =
+                convert_lex_str(new_key_part->field_name);
+            //通过column查tablemeta, 然后差当前的onion在不在那个tablemeta里面
+            // > the onion may not exist; ie oPLAIN with SENSITIVE and not
+            // an AUTO INCREMENT column
+            const FieldMeta &fm = a.getFieldMeta(tm, field_name);
+            const OnionMeta *const om = fm.getOnionMeta(o);
+            if (NULL == om) {
+                break;
+            }
+            //如果存在, 那么新的column的名字就是洋葱的名字, 然后new_key的column就确定了
+            //可以看到, 对于索引里面的每个field, 都选择一个洋葱, 如果没有合适的, 则不选择.
+            new_key_part->field_name =
+                string_to_lex_str(om->getAnonOnionName());
+            new_key->columns.push_back(new_key_part);
+        }
+    }
+
+    //上面, 对于一个key来说, 可以查三个洋葱
+    //对于每个洋葱,都可能构造一个key, 这是根据这个key对应的columns里面有没有洋葱, 有则选进来. 所以, 列扩展了以后, 索引也扩展了.
+    //主键特殊处理, 之根据一个洋葱构造.
+    // Only create one PRIMARY KEY.
+    if (Key::PRIMARY == key.type) {
+        if (output_keys.size() > 0) {
+            return std::vector<Key *>({output_keys.front()});
+        }
+    }
+
+    return output_keys;
+}
+
+
+
 
 // 'seed_lex' and 'out_lex' can be the same object.
 void
@@ -363,7 +434,7 @@ highLevelRewriteKey(const TableMeta &tm, const LEX &seed_lex,
                 // -----------------------------
                 //         Rewrite INDEX
                 // -----------------------------
-                auto new_keys = rewrite_key(tm, *key, a);
+                auto new_keys = rewrite_key1(tm, *key, a);
                 out_list.concat(vectorToListWithTHD(new_keys));
 
                 return out_list;
@@ -372,6 +443,17 @@ highLevelRewriteKey(const TableMeta &tm, const LEX &seed_lex,
     return;
 }
 
+void 
+highLevelRewriteForeignKey(){
+
+
+
+
+}
+
+
+
+
 std::string
 bool_to_string(bool b)
 {
@@ -425,7 +507,6 @@ createAndRewriteField(Analysis &a, Create_field * const cf,
     cf->flags = cf->flags | UNSIGNED_FLAG;
 
     const std::string &name = std::string(cf->field_name);
-    std::cout<<RED_BEGIN<<name<<":"<<cf->sql_type<<COLOR_END<<std::endl;
     std::unique_ptr<FieldMeta>
         fm(new FieldMeta(*cf, a.getMasterKey().get(),
                          a.getDefaultSecurityRating(), tm->leaseCount(),

main/rewrite_util.hh

@@ -53,6 +53,11 @@ void
 highLevelRewriteKey(const TableMeta &tm, const LEX &seed_lex,
                     LEX *const out_lex, const Analysis &a);
 
+//added
+void 
+highLevelRewriteForeignKey();
+
+
 std::string
 bool_to_string(bool b);