From e2242cffd230d96acb0b7b8fc5925e77a8f945bf Mon Sep 17 00:00:00 2001
From: Steven Zou <szou@vmware.com>
Date: Fri, 27 Oct 2017 18:16:16 +0800
Subject: [PATCH] define filter interfaces for replication service
 including:interface Filter,Converter and FilterChain and other supporting
 models

---
 src/replication/consts.go               | 10 ++++++++++
 src/replication/models/filter_config.go |  7 +++++++
 src/replication/models/filter_item.go   | 19 +++++++++++++++++++
 src/replication/source/convertor.go     | 16 ++++++++++++++++
 src/replication/source/filter.go        | 21 +++++++++++++++++++++
 src/replication/source/filter_chain.go  | 21 +++++++++++++++++++++
 6 files changed, 94 insertions(+)
 create mode 100644 src/replication/consts.go
 create mode 100644 src/replication/models/filter_config.go
 create mode 100644 src/replication/models/filter_item.go
 create mode 100644 src/replication/source/convertor.go
 create mode 100644 src/replication/source/filter.go
 create mode 100644 src/replication/source/filter_chain.go

diff --git a/src/replication/consts.go b/src/replication/consts.go
new file mode 100644
index 000000000..10075bcb3
--- /dev/null
+++ b/src/replication/consts.go
@@ -0,0 +1,10 @@
+package replication
+
+const (
+	//Kind of filter item is 'project'
+	filterItemKindProject = "project"
+	//Kind of filter item is 'repository'
+	filterItemKindRepository = "repository"
+	//Kind of filter item is 'tag'
+	filterItemKindTag = "tag"
+)
diff --git a/src/replication/models/filter_config.go b/src/replication/models/filter_config.go
new file mode 100644
index 000000000..cdc8e60a9
--- /dev/null
+++ b/src/replication/models/filter_config.go
@@ -0,0 +1,7 @@
+package models
+
+//FilterConfig is data model to provide configurations to the filters.
+type FilterConfig struct {
+	//The pattern for fuzzy matching
+	pattern string
+}
diff --git a/src/replication/models/filter_item.go b/src/replication/models/filter_item.go
new file mode 100644
index 000000000..9565ac447
--- /dev/null
+++ b/src/replication/models/filter_item.go
@@ -0,0 +1,19 @@
+package models
+
+//FilterItem is the general data model represents the filtering resources which are used as input and output for the filters.
+type FilterItem struct {
+
+	//The kind of the filtering resources. Support 'project','repository' and 'tag' etc.
+	kind string
+
+	//The key value of resource which can be used to filter out the resource matched with specified pattern.
+	//E.g:
+	//kind == 'project', value will be project name;
+	//kind == 'repository', value will be repository name
+	//kind == 'tag', value will be tag name.
+	value string
+
+	//Extension placeholder.
+	//To append more additional information if required by the filter.
+	metadata map[string]interface{}
+}
diff --git a/src/replication/source/convertor.go b/src/replication/source/convertor.go
new file mode 100644
index 000000000..d07aafd35
--- /dev/null
+++ b/src/replication/source/convertor.go
@@ -0,0 +1,16 @@
+package source
+
+import (
+	"github.com/vmware/harbor/src/replication/models"
+)
+
+//Convertor is designed to covert the format of output from upstream filter to the input format
+//required by the downstream filter if needed.
+//Each convertor covers only one specified conversion process between the two filters.
+//E.g:
+//If project filter connects to repository filter, then one convertor should be defined for this connection;
+//If project filter connects to tag filter, then another one should be defined. The above one can not be reused.
+type Convertor interface {
+	//Accept the items from upstream filter as input and then covert them to the required format and returned.
+	Convert(itemsOfUpstream []models.FilterItem) (itemsOfDownstream []models.FilterItem)
+}
diff --git a/src/replication/source/filter.go b/src/replication/source/filter.go
new file mode 100644
index 000000000..831e4b017
--- /dev/null
+++ b/src/replication/source/filter.go
@@ -0,0 +1,21 @@
+package source
+
+import (
+	"github.com/vmware/harbor/src/replication/models"
+)
+
+//Filter define the operations of selecting the matched resources from the candidates
+//according to the specified pattern.
+type Filter interface {
+	//Initialize the filter with specified configurations like pattern definition
+	Init(config models.FilterConfig)
+
+	//Set Convertor if necessary
+	SetConvertor(convertor Convertor)
+
+	//Return the convertor if existing or nil if never set
+	GetConvertor() Convertor
+
+	//Filter the items
+	DoFilter(filterItems []models.FilterItem) []models.FilterItem
+}
diff --git a/src/replication/source/filter_chain.go b/src/replication/source/filter_chain.go
new file mode 100644
index 000000000..156ed6fc6
--- /dev/null
+++ b/src/replication/source/filter_chain.go
@@ -0,0 +1,21 @@
+package source
+
+import (
+	"github.com/vmware/harbor/src/replication/models"
+)
+
+//FilterChain is the interface to define the operations of coordinating multiple filters
+//to work together as a whole pipeline.
+//E.g:
+//(original resources)---->[project filter]---->[repository filter]---->[tag filter]---->[......]---->(filter resources)
+type FilterChain interface {
+	//Build the filter chain with the filters provided;
+	//if failed, an error will be returned.
+	Build(filter []Filter) error
+
+	//Return all the filters in the chain.
+	Filters() []Filter
+
+	//Filter the items and returned the filtered items via the appended filters in the chain.
+	DoFilter(filterItems []models.FilterItem) []models.FilterItem
+}