Introduce schema_mutations

configure.py

@@ -240,6 +240,7 @@ scylla_core = (['database.cc',
                  'row_cache.cc',
                  'frozen_mutation.cc',
                  'memtable.cc',
+                 'schema_mutations.cc',
                  'release.cc',
                  'utils/logalloc.cc',
                  'utils/large_bitset.cc',

database_fwd.hh

@@ -32,6 +32,9 @@ class mutation_partition;
 class schema;
 class column_definition;
 
+// schema_mutations.hh
+class schema_mutations;
+
 // keys.hh
 class exploded_clustering_prefix;
 class partition_key;

schema_mutations.cc

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2015 ScyllaDB
+ */
+
+/*
+ * This file is part of Scylla.
+ *
+ * Scylla is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Scylla is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Scylla.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "schema_mutations.hh"
+#include "canonical_mutation.hh"
+#include "db/schema_tables.hh"
+#include "md5_hasher.hh"
+
+void schema_mutations::copy_to(std::vector<mutation>& dst) const {
+    dst.push_back(_columnfamilies);
+    dst.push_back(_columns);
+}
+
+table_schema_version schema_mutations::digest() const {
+    md5_hasher h;
+    feed_hash(h, _columnfamilies);
+    feed_hash(h, _columns);
+    return utils::UUID_gen::get_name_UUID(h.finalize());
+}
+
+bool schema_mutations::operator==(const schema_mutations& other) const {
+    return _columnfamilies == other._columnfamilies
+           && _columns == other._columns;
+}
+
+bool schema_mutations::operator!=(const schema_mutations& other) const {
+    return !(*this == other);
+}
+
+bool schema_mutations::live() const {
+    return _columnfamilies.live_row_count() > 0 || _columns.live_row_count() > 0;
+}

schema_mutations.hh

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2015 ScyllaDB
+ */
+
+/*
+ * This file is part of Scylla.
+ *
+ * Scylla is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Scylla is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Scylla.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <vector>
+#include "mutation.hh"
+#include "schema.hh"
+
+// Commutative representation of table schema
+class schema_mutations {
+    mutation _columnfamilies;
+    mutation _columns;
+public:
+    schema_mutations(mutation columnfamilies, mutation columns)
+            : _columnfamilies(std::move(columnfamilies))
+            , _columns(std::move(columns))
+    { }
+
+    schema_mutations(schema_mutations&&) = default;
+    schema_mutations& operator=(schema_mutations&&) = default;
+    schema_mutations(const schema_mutations&) = default;
+    schema_mutations& operator=(const schema_mutations&) = default;
+
+    void copy_to(std::vector<mutation>& dst) const;
+
+    const mutation& columnfamilies_mutation() const {
+        return _columnfamilies;
+    }
+
+    const mutation& columns_mutation() const {
+        return _columns;
+    }
+
+    table_schema_version digest() const;
+
+    bool operator==(const schema_mutations&) const;
+    bool operator!=(const schema_mutations&) const;
+
+    // Returns true iff any mutations contain any live cells
+    bool live() const;
+};