1 files changed, 122 insertions, 0 deletions
diff --git a/snapshot/snapshot.go b/snapshot/snapshot.go
new file mode 100644
index 000000000..294f8b611
--- /dev/null
+++ b/snapshot/snapshot.go
@@ -0,0 +1,122 @@
+// Copyright 2021 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package snapshot
+
+import (
+	"path/filepath"
+	"sort"
+
+	"android/soong/android"
+)
+
+// This file contains singletons to capture snapshots. This singleton will generate snapshot of each target
+// image, and capturing snapshot module will be delegated to each module which implements GenerateSnapshotAction
+// function and register with RegisterSnapshotAction.
+
+var pctx = android.NewPackageContext("android/soong/snapshot")
+
+type SnapshotSingleton struct {
+	// Name, e.g., "vendor", "recovery", "ramdisk".
+	name string
+
+	// Make variable that points to the snapshot file, e.g.,
+	// "SOONG_RECOVERY_SNAPSHOT_ZIP".
+	makeVar string
+
+	// Path to the snapshot zip file.
+	snapshotZipFile android.OptionalPath
+
+	// Implementation of the image interface specific to the image
+	// associated with this snapshot (e.g., specific to the vendor image,
+	// recovery image, etc.).
+	Image SnapshotImage
+
+	// Whether this singleton is for fake snapshot or not.
+	// Fake snapshot is a snapshot whose prebuilt binaries and headers are empty.
+	// It is much faster to generate, and can be used to inspect dependencies.
+	Fake bool
+}
+
+// Interface of function to capture snapshot from each module
+type GenerateSnapshotAction func(snapshot SnapshotSingleton, ctx android.SingletonContext, snapshotArchDir string) android.Paths
+
+var snapshotActionList []GenerateSnapshotAction
+
+// Register GenerateSnapshotAction function so it can be called while generating snapshot
+func RegisterSnapshotAction(x GenerateSnapshotAction) {
+	snapshotActionList = append(snapshotActionList, x)
+}
+
+func (c *SnapshotSingleton) GenerateBuildActions(ctx android.SingletonContext) {
+	if !c.Image.shouldGenerateSnapshot(ctx) {
+		return
+	}
+
+	var snapshotOutputs android.Paths
+
+	// Snapshot zipped artifacts will be captured under {SNAPSHOT_ARCH} directory
+
+	snapshotDir := c.name + "-snapshot"
+	if c.Fake {
+		// If this is a fake snapshot singleton, place all files under fake/ subdirectory to avoid
+		// collision with real snapshot files
+		snapshotDir = filepath.Join("fake", snapshotDir)
+	}
+	snapshotArchDir := filepath.Join(snapshotDir, ctx.DeviceConfig().DeviceArch())
+
+	for _, f := range snapshotActionList {
+		snapshotOutputs = append(snapshotOutputs, f(*c, ctx, snapshotArchDir)...)
+	}
+
+	// All artifacts are ready. Sort them to normalize ninja and then zip.
+	sort.Slice(snapshotOutputs, func(i, j int) bool {
+		return snapshotOutputs[i].String() < snapshotOutputs[j].String()
+	})
+
+	zipPath := android.PathForOutput(
+		ctx,
+		snapshotDir,
+		c.name+"-"+ctx.Config().DeviceName()+".zip")
+	zipRule := android.NewRuleBuilder(pctx, ctx)
+
+	// filenames in rspfile from FlagWithRspFileInputList might be single-quoted. Remove it with tr
+	snapshotOutputList := android.PathForOutput(
+		ctx,
+		snapshotDir,
+		c.name+"-"+ctx.Config().DeviceName()+"_list")
+	rspFile := snapshotOutputList.ReplaceExtension(ctx, "rsp")
+	zipRule.Command().
+		Text("tr").
+		FlagWithArg("-d ", "\\'").
+		FlagWithRspFileInputList("< ", rspFile, snapshotOutputs).
+		FlagWithOutput("> ", snapshotOutputList)
+
+	zipRule.Temporary(snapshotOutputList)
+
+	zipRule.Command().
+		BuiltTool("soong_zip").
+		FlagWithOutput("-o ", zipPath).
+		FlagWithArg("-C ", android.PathForOutput(ctx, snapshotDir).String()).
+		FlagWithInput("-l ", snapshotOutputList)
+
+	zipRule.Build(zipPath.String(), c.name+" snapshot "+zipPath.String())
+	zipRule.DeleteTemporaryFiles()
+	c.snapshotZipFile = android.OptionalPathForPath(zipPath)
+}
+
+func (c *SnapshotSingleton) MakeVars(ctx android.MakeVarsContext) {
+	ctx.Strict(
+		c.makeVar,
+		c.snapshotZipFile.String())
+}