LogDog: Add log rendering view.

client/cmd/logdog_cat/coordinatorSource.go

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package main
 
 import (
         "errors"
+        "math"
         "sync"
         "time"
 
         "github.com/luci/luci-go/common/clock"
         "github.com/luci/luci-go/common/logdog/coordinator"
         "github.com/luci/luci-go/common/logdog/fetcher"
         "github.com/luci/luci-go/common/logdog/types"
         log "github.com/luci/luci-go/common/logging"
         "github.com/luci/luci-go/common/proto/logdog/logpb"
         "golang.org/x/net/context"
@@ skipping 16 matching lines @@
         tidx   types.MessageIndex
 
         state coordinator.LogStream
 }
 
 func (s *coordinatorSource) LogEntries(c context.Context, req *fetcher.LogRequest) (
         []*logpb.LogEntry, types.MessageIndex, error) {
         s.Lock()
         defer s.Unlock()
 
-        p := coordinator.NewGetParams().Limit(int(req.Bytes), req.Count).Index(req.Index)
+        // Limit our constraints to int32.
+        bytes, count := req.Bytes, req.Count
+        if bytes > math.MaxInt32 {
+                bytes = math.MaxInt32
+        }

[Ryan Tseng, 2016/02/08 22:56:55]

log warning?

[dnj (Google), 2016/02/09 02:50:03]

No need. The "bytes" and "count" parameters are permitted to be internally
reduced as an implementation detail. The supplied parameters are just maximums.

+        if count > math.MaxInt32 {
+                count = math.MaxInt32
+        }
+
+        p := coordinator.NewGetParams().Limit(int32(bytes), int32(count)).Index(req.Index)
 
         // If we haven't terminated, use this opportunity to fetch/update our stream
         // state.
         if s.tidx < 0 {
                 p = p.State(&s.state)
         }
 
         for {
                 logs, err := s.stream.Get(c, p)
                 switch err {
@@ skipping 28 matching lines @@
         defer s.Unlock()
         return s.state
 }
 
 func (s *coordinatorSource) descriptor() (*logpb.LogStreamDescriptor, error) {
         if d := s.state.Desc; d != nil {
                 return d, nil
         }
         return nil, errors.New("no descriptor loaded")
 }