#424

backend/app/services/shared_resource_id_allocator.rb

@@ -0,0 +1,56 @@
+require 'digest'
+
+
+class SharedResourceIdAllocator
+  SPACES = {
+      'tags' => ['tags', 'external_tags'],
+      'wiki' => ['tag_descriptions', 'tag_groups'] }.freeze
+  LOCK_TIMEOUT = 10
+
+  def self.assign! record
+    space, tables = SPACES.find { |_name, names| names.include?(record.class.table_name) }
+    raise ArgumentError, 'Unknown shared ID resource' unless tables
+
+    connection = record.class.connection
+    transaction = record.class.current_transaction
+    raise ActiveRecord::ActiveRecordError, 'Shared ID requires a transaction' unless transaction.open?
+
+    database = connection.pool.db_config.database
+    name = "btrc:ids:#{ Digest::SHA256.hexdigest(database)[0, 16] }:#{ space }"
+    quoted_name = connection.quote(name)
+    acquired = record.class.uncached do
+      connection.select_value("SELECT GET_LOCK(#{ quoted_name }, #{ LOCK_TIMEOUT })")
+    end
+    unless acquired.to_i == 1
+      raise ActiveRecord::LockWaitTimeout, "Shared ID lock unavailable: #{ space }"
+    end
+
+    release = lambda do
+      result = record.class.uncached do
+        connection.select_value("SELECT RELEASE_LOCK(#{ quoted_name })")
+      end
+      unless result.to_i == 1
+        raise ActiveRecord::ActiveRecordError, "Shared ID lock release failed: #{ space }"
+      end
+    end
+    begin
+      transaction.after_commit(&release)
+      transaction.after_rollback(&release)
+    rescue StandardError
+      release.call
+      raise
+    end
+
+    return if record.id.present?
+
+    # Locking reads see committed maxima even after earlier repeatable reads.
+    maxima = record.class.uncached do
+      tables.map do |table|
+        quoted_table = connection.quote_table_name(table)
+        connection.select_value(
+            "SELECT id FROM #{ quoted_table } ORDER BY id DESC LIMIT 1 FOR UPDATE").to_i
+      end
+    end
+    record.id = maxima.max + 1
+  end
+end

backend/app/services/tag_description_operation.rb

@@ -8,9 +8,9 @@ class TagDescriptionOperation
           tag_id: tag.id, language_code: LANGUAGE_CODE)
 
       page = Wiki::CompatibilityWriter.create!(
-          tag_name: tag.tag_name(LANGUAGE_CODE), body:, created_by_user:, message:)
+          tag_name: compatibility_tag_name(tag), body:, created_by_user:, message:)
       revision = page.wiki_revisions.order(id: :desc).first
-      record_version!(tag:, revision:, body:, user: created_by_user,
+      record_version!(tag:, revision:, body: revision.body, user: created_by_user,
                       description: nil)
       page
     end
@@ -22,7 +22,20 @@ class TagDescriptionOperation
       tag.lock!
       description = TagDescription.lock.find_by!(
           tag_id: tag.id, language_code: LANGUAGE_CODE)
-      page = WikiPage.lock.find(description.id)
+      tag_name = compatibility_tag_name(tag)
+      page = WikiPage.lock.find_by(tag_name_id: tag_name.id)
+      unless page
+        versions = TagDescriptionVersion.where(tag_id: tag.id, language_code: LANGUAGE_CODE)
+        if base_revision_id.present? && versions.maximum(:id) != base_revision_id.to_i
+          raise Wiki::Commit::Conflict, '競合が発生してゐます．'
+        end
+        page = Wiki::CompatibilityWriter.create!(
+            tag_name:, body:, created_by_user: updated_by_user, message:)
+        revision = page.current_revision
+        record_version!(tag:, revision:, body: revision.body,
+                        user: updated_by_user, description:)
+        next revision
+      end
       revision = Wiki::CompatibilityWriter.update!(
           page:, body:, updated_by_user:, message:,
           base_revision_id:)
@@ -34,6 +47,11 @@ class TagDescriptionOperation
     end
   end
 
+  def self.compatibility_tag_name tag
+    tag.tag_name(LANGUAGE_CODE) || TagName.find_by!(id: tag.tag_name_id,
+                                                  language_code: LANGUAGE_CODE)
+  end
+
   def self.record_version! tag:, revision:, body:, user:, description:
     version_no = description ? description.version_no + 1 : 1
     TagDescriptionVersion.create!(
@@ -44,7 +62,7 @@ class TagDescriptionOperation
       description.update!(body:, version_no:, updated_by_user_id: user.id)
     else
       TagDescription.create!(
-          id: revision.wiki_page_id, tag_id: tag.id,
+          tag_id: tag.id,
           language_code: LANGUAGE_CODE, version_no:, body:,
           created_by_user_id: user.id, updated_by_user_id: user.id)
     end

backend/app/services/tag_group_operation.rb

@@ -349,7 +349,7 @@ class TagGroupOperation
       tag_name.primary_flg = true
       tag_name.auto_generated = false
       tag_name.save!
-      Wiki::Commit.create_legacy_content!(tag_name:, body:, created_by_user: actor)
+      Wiki::CompatibilityWriter.create!(tag_name:, body:, created_by_user: actor)
     end
     nil
   end

backend/app/services/wiki/commit.rb

@@ -8,12 +8,13 @@ module Wiki
     end
 
     def self.create_content! tag_name:, body:, created_by_user:, message: nil
-      if tag_name.tag && tag_name.language_code == 'ja'
+      if tag_name.tag && tag_name.language_code == 'ja' && !tag_name.name.include?(':')
         return TagDescriptionOperation.create!(
             tag: tag_name.tag, body:, created_by_user:, message:)
       end
 
-      create_legacy_content!(tag_name:, body:, created_by_user:, message:)
+      tag_name.errors.add(:base, :invalid)
+      raise ActiveRecord::RecordInvalid, tag_name
     end
 
     def self.create_legacy_content! tag_name:, body:, created_by_user:, message: nil
@@ -42,14 +43,17 @@ module Wiki
     end
 
     def self.content! page:, body:, created_user:, message: nil, base_revision_id: nil
-      description = TagDescription.find_by(id: page.id)
-      if description
+      description = TagDescription.find_by(tag_id: page.tag_name.tag_id, language_code: 'ja')
+      description ||= TagDescription.joins(:tag).find_by(
+          tags: { tag_name_id: page.tag_name_id }, language_code: 'ja')
+      if description && !page.title.include?(':')
         return TagDescriptionOperation.update!(
             tag: description.tag, body:, updated_by_user: created_user,
             message:, base_revision_id:)
       end
 
-      legacy_content!(page:, body:, created_user:, message:, base_revision_id:)
+      page.errors.add(:base, :invalid)
+      raise ActiveRecord::RecordInvalid, page
     end
 
     def self.legacy_content! page:, body:, created_user:, message: nil,

backend/app/services/wiki/compatibility_writer.rb

@@ -1,8 +1,16 @@
 module Wiki
   class CompatibilityWriter
     def self.create! tag_name:, body:, created_by_user:, message: nil
-      Commit.create_legacy_content!(
-          tag_name:, body:, created_by_user:, message:)
+      ApplicationRecord.transaction do
+        tag_name.lock!
+        page = WikiPage.lock.find_by(tag_name_id: tag_name.id)
+        if page
+          update!(page:, body:, updated_by_user: created_by_user, message:)
+          page
+        else
+          Commit.create_legacy_content!(tag_name:, body:, created_by_user:, message:)
+        end
+      end
     end
 
     def self.update! page:, body:, updated_by_user:, message: nil,
@@ -23,7 +31,9 @@ module Wiki
         end
       end
 
-      return if Commit.normalise_body(page.body) == normalised
+      if Commit.normalise_body(page.body) == normalised && page.wiki_revisions.exists?
+        return
+      end
 
       Commit.legacy_content!(
           page:, body: normalised, created_user: updated_by_user, message:,