Add LogDog log stream fetcher code.

web/inc/logdog-stream/client.ts

+/*
+  Copyright 2016 The LUCI Authors. All rights reserved.
+  Use of this source code is governed under the Apache License, Version 2.0
+  that can be found in the LICENSE file.
+*/
+
+///<reference path="logdog.ts" />
+///<reference path="../rpc/client.ts" />
+
+namespace LogDog {
+
+  export type GetRequest = {
+    project: string; path: string; state: boolean; index: number;
+
+    nonContiguous?: boolean;
+    byteCount?: number;
+    logCount?: number;
+  };
+
+  export type TailRequest = {project: string; path: string; state: boolean;};
+
+  // Type of a "Get" or "Tail" response (protobuf).
+  export type GetResponse = {state: any; desc: any; logs: any[];};
+
+  /** Configurable set of log stream query parameters. */
+  export type QueryRequest = {
+    project: string; getMeta?: boolean; path?: string; contentType?: string;
+    streamType?: LogDog.StreamType;
+    purged?: boolean;
+    newer?: Date;
+    older?: Date;
+    protoVersion?: string;
+    tags?: {[key: string]: string};
+  };
+
+  /** The result of a log stream query. */
+  export type QueryResult = {
+    stream: LogDog.StreamPath; state?: LogDog.LogStreamState;
+    desc?: LogDog.LogStreamDescriptor;
+  };
+
+  export class Client {
+    debug = false;
+
+    constructor(private client: luci.Client) {}
+
+    /** Get executes a Get RPC. */
+    get(req: GetRequest): Promise<GetResponse> {
+      if (this.debug) {
+        console.log('logdog.Logs.Get:', req);
+      }
+      return this.client.call('logdog.Logs', 'Get', req);
+    }
+
+    /** Tail executes a Tail RPC. */
+    tail(stream: StreamPath, state: boolean): Promise<GetResponse> {
+      let request: TailRequest = {
+        project: stream.project,
+        path: stream.path,
+        state: state,
+      };
+
+      if (this.debug) {
+        console.log('logdog.Logs.Tail:', request);
+      }
+      return this.client.call('logdog.Logs', 'Tail', request);
+    }
+
+    /**
+     * Query executes a Query RPC.
+     *
+     * @param params The query request parameters.
+     * @param cursor The cursor to supply. Can be empty for no cursor.
+     * @param limit The maximum number of query results to return.
+     *
+     * @return a Promise that resolves to the query results and continuation
+     *     cursor. The cursor may be empty if the query finished.
+     */
+    query(params: QueryRequest, cursor = '', limit = 0):
+        Promise<[QueryResult[], string]> {
+      let project = params.project;
+      let body: any = {
+        project: project,
+        path: params.path,
+        content_type: params.contentType,
+        proto_version: params.protoVersion,
+        tags: params.tags,
+
+        next: cursor,
+        max_results: limit,
+      };
+
+      let trinary = (v: boolean): string => {
+        return ((v) ? 'YES' : 'NO');
+      };
+      if (params.purged != null) {
+        body.purged = trinary(params.purged);
+      }
+
+      if (params.streamType !== undefined) {
+        body.stream_type = {value: LogDog.StreamType[params.streamType]};
+      }
+      if (params.newer) {
+        body.newer = params.newer.toISOString();
+      }
+      if (params.older) {
+        body.older = params.older.toISOString();
+      }
+
+      type responseType = {
+        streams: {
+          path: string,
+          state: any,
+          desc: any,
+        }[];
+        next: string;
+      };
+
+      return this.client.call('logdog.Logs', 'Query', body)
+          .then((resp: responseType): [QueryResult[], string] => {
+
+            // Package the response in QueryResults.
+            let results = (resp.streams || []).map(entry => {
+              let res: QueryResult = {
+                stream: new LogDog.StreamPath(project, entry.path),
+              };
+              if (entry.state) {
+                res.state = LogDog.LogStreamState.make(entry.state);
+              }
+              if (entry.desc) {
+                res.desc = LogDog.LogStreamDescriptor.make(entry.desc);
+              }
+              return res;
+            });
+            return [results, resp.next];
+          });
+    }
+  }
+}