From b223e6eed3eab19bd455d70ff37435eb54906914 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Markus=20M=C3=A4kel=C3=A4?= <markus.makela@mariadb.com>
Date: Mon, 30 Sep 2019 09:57:07 +0300
Subject: [PATCH] MXS-2264: Add support for RENAME TABLE

RENAME TABLE is now fully supported and works as expected. With the fix to
table versioning, the new table name will receive the latest version
number.
---
 server/modules/routing/avrorouter/avro_rbr.cc | 12 +++-
 server/modules/routing/avrorouter/rpl.cc      | 55 ++++++++++++++++++-
 server/modules/routing/avrorouter/rpl.hh      |  1 +
 3 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/server/modules/routing/avrorouter/avro_rbr.cc b/server/modules/routing/avrorouter/avro_rbr.cc
index 3258caef2..ff3e6d517 100644
--- a/server/modules/routing/avrorouter/avro_rbr.cc
+++ b/server/modules/routing/avrorouter/avro_rbr.cc
@@ -804,6 +804,13 @@ bool is_alter_table_statement(pcre2_code* alter_table_re, char* ptr, size_t len)
     return rc > 0;
 }
 
+bool is_rename_table_statement(const char* sql)
+{
+    int err = 0;
+    const char* pattern = "(?i)^\\s*rename\\s*table\\s*";
+    return mxs_pcre2_simple_match(pattern, sql, 0, &err) == MXS_PCRE2_MATCH;
+}
+
 /** Database name offset */
 #define DBNM_OFF 8
 
@@ -1006,7 +1013,10 @@ void Rpl::handle_query_event(REP_HEADER* hdr, uint8_t* ptr)
             MXS_ERROR("Alter statement to table '%s' has no preceding create statement.", ident);
         }
     }
-    // TODO: Add COMMIT handling for non-transactional tables
+    else if (is_rename_table_statement(sql))
+    {
+        table_create_rename(db, sql, sql + len);
+    }
 
     MXS_FREE(tmp);
 }
diff --git a/server/modules/routing/avrorouter/rpl.cc b/server/modules/routing/avrorouter/rpl.cc
index c736acb2f..7142553d0 100644
--- a/server/modules/routing/avrorouter/rpl.cc
+++ b/server/modules/routing/avrorouter/rpl.cc
@@ -934,7 +934,7 @@ static const char* get_tok(const char* sql, int* toklen, const char* end)
     int depth = 0;
     while (start + len < end)
     {
-        if (isspace(start[len]) && depth == 0)
+        if (depth == 0 && (isspace(start[len]) || start[len] == ','))
         {
             *toklen = len;
             return start;
@@ -1429,6 +1429,59 @@ bool Rpl::table_create_alter(STableCreateEvent create, const char* sql, const ch
     return true;
 }
 
+void Rpl::table_create_rename(const std::string& db, const char* sql, const char* end)
+{
+    const char* tbl = strcasestr(sql, "table");
+
+    if (const char* def = strchr(tbl, ' '))
+    {
+        int len = 0;
+        const char* tok = def;
+
+        while (tok && (tok = get_tok(tok + len, &len, end)))
+        {
+            char old_name[len + 1];
+            make_avro_token(old_name, tok, len);
+
+            // Skip over the TO keyword
+            tok = get_tok(tok + len, &len, end);
+            tok = get_tok(tok + len, &len, end);
+
+            char new_name[len + 1];
+            make_avro_token(new_name, tok, len);
+
+            std::string from = strchr(old_name, '.') ? old_name : db + "." + old_name;
+            auto it = m_created_tables.find(from);
+
+            if (it != m_created_tables.end())
+            {
+                auto& create = it->second;
+
+                if (char* p = strchr(new_name, '.'))
+                {
+                    *p++ = '\0';
+                    create->database = new_name;
+                    create->table = p;
+                }
+                else
+                {
+                    create->database = db;
+                    create->table = new_name;
+                }
+
+                MXS_INFO("Renamed '%s' to '%s'", from.c_str(), create->id().c_str());
+
+                create->version = ++m_versions[create->id()];
+                create->was_used = false;
+                rename_table_create(create, from);
+            }
+
+            tok = get_next_def(tok, end);
+            len = 0;
+        }
+    }
+}
+
 bool Rpl::table_matches(const std::string& ident)
 {
     bool rval = false;
diff --git a/server/modules/routing/avrorouter/rpl.hh b/server/modules/routing/avrorouter/rpl.hh
index 5eb1c9296..311c5368a 100644
--- a/server/modules/routing/avrorouter/rpl.hh
+++ b/server/modules/routing/avrorouter/rpl.hh
@@ -294,5 +294,6 @@ private:
     bool              save_and_replace_table_create(STableCreateEvent created);
     bool              rename_table_create(STableCreateEvent created, const std::string& old_id);
     bool              table_create_alter(STableCreateEvent create, const char* sql, const char* end);
+    void              table_create_rename(const std::string& db, const char* sql, const char* end);
     bool              table_matches(const std::string& ident);
 };