logdog: Add bundler library.

client/internal/logdog/butler/bundler/sizer_fast_test.go

+// Copyright 2015 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 bundler
+
+import (
+        "bytes"
+        "fmt"
+        "strings"
+        "testing"
+
+        "github.com/golang/protobuf/proto"
+        "github.com/luci/luci-go/common/logdog/protocol"
+        . "github.com/smartystreets/goconvey/convey"
+)
+
+// A proto.Message implementation with test fields.
+type testMessage struct {
+        U64 *uint64 `protobuf:"varint,1,opt,name=u64"`
+}
+
+func (t *testMessage) Reset()         {}
+func (t *testMessage) String() string { return "" }
+func (t *testMessage) ProtoMessage()  {}
+
+func TestFastSizerVarintLength(t *testing.T) {
+        Convey(`A test message`, t, func() {
+                for _, threshold := range []uint64{
+                        0,
+                        0x80,
+                        0x4000,
+                        0x200000,
+                        0x100000000,
+                        0x800000000,
+                        0x40000000000,
+                        0x2000000000000,
+                        0x100000000000000,
+                        0x8000000000000000,
+                } {
+
+                        for _, delta := range []int64{
+                                -2,
+                                -1,
+                                0,
+                                1,
+                                2,
+                        } {
+                                // Add "delta" to "threshold" in a uint64-aware manner.
+                                u64 := threshold
+                                if delta >= 0 {
+                                        u64 += uint64(delta)
+                                } else {
+                                        if u64 < uint64(-delta) {
+                                                continue
+                                        }
+                                        u64 -= uint64(-delta)
+                                }
+
+                                expected := varintLength(u64)
+                                Convey(fmt.Sprintf(`Testing threshold 0x%x should encode to varint size %d`, u64, expected), func() {
+                                        m := &testMessage{
+                                                U64: &u64,
+                                        }
+                                        // Note: "-1" is for the "U64" field tag, "1", which has encoded size of 1.
+                                        So(expected, ShouldEqual, proto.Size(m)-1)
+                                })
+                        }
+                }
+        })
+}
+
+func TestFastSizer(t *testing.T) {
+        Convey(`A fastSizer instance`, t, func() {
+                source := "test source"
+                u64 := uint64(0x1337d06)
+                bundle := &protocol.ButlerLogBundle{
+                        Source: &source,
+                        Timestamp: &protocol.Timestamp{
+                                UsFromEpoch: &u64,
+                        },
+                }
+                s := NewFastSizer(bundle).(*fastSizer)
+
+                Convey(`Has a valid initial size.`, func() {
+                        So(s.Size(), ShouldEqual, proto.Size(bundle))
+
+                        Convey(`Still has a valid size after Undo().`, func() {
+                                s.Undo()
+                                So(s.Size(), ShouldEqual, proto.Size(bundle))
+                        })
+                })
+
+                Convey(`After appending a bundle entry`, func() {
+                        be := &protocol.ButlerLogBundle_Entry{
+                                Secret: bytes.Repeat([]byte{0x55, 0xAA}, 16),
+                        }
+                        s.Append(be, nil)
+                        bundle.Entries = append(bundle.Entries, be)
+                        So(s.Size(), ShouldEqual, proto.Size(bundle))
+
+                        Convey(`Can undo the Append().`, func() {
+                                s.Undo()
+                                bundle.Entries = nil
+                                So(s.Size(), ShouldEqual, proto.Size(bundle))
+                        })
+
+                        Convey(`After appending log entries`, func() {
+                                for i := 0; i < 10; i++ {
+                                        log := &protocol.LogEntry{
+                                                Lines: []string{
+                                                        strings.Repeat("A", i*10),
+                                                        strings.Repeat("B", i*20),
+                                                },
+                                                Data: [][]byte{
+                                                        bytes.Repeat([]byte{0x55, 0xAA}, i*10),
+                                                        bytes.Repeat([]byte{0x10, 0x6d, 0x06}, i*20),
+                                                },
+                                        }
+
+                                        s.Append(be, log)
+                                        be.Logs = append(be.Logs, log)
+                                        So(s.Size(), ShouldEqual, proto.Size(bundle))
+                                }
+
+                                Convey(`Whole bundle should equal the actual protobuf size.`, func() {
+                                        So(s.Size(), ShouldEqual, proto.Size(bundle))
+                                })
+
+                                Convey(`Can undo the Append().`, func() {
+                                        s.Undo()
+                                        be.Logs = be.Logs[:len(be.Logs)-1]
+                                        So(s.Size(), ShouldEqual, proto.Size(bundle))
+                                })
+                        })
+                })
+        })
+}