From b2b48c2a4d03b463bc799782e40d4a53674fcb31 Mon Sep 17 00:00:00 2001
From: Preston Van Loon <preston@prysmaticlabs.com>
Date: Wed, 30 Oct 2019 19:05:37 -0400
Subject: [PATCH] Extract state from db (#3889)

---
 beacon-chain/core/state/interop/BUILD.bazel |  5 +-
 beacon-chain/db/filters/BUILD.bazel         |  5 +-
 tools/extractor/BUILD.bazel                 | 20 ++++++++
 tools/extractor/main.go                     | 51 +++++++++++++++++++++
 4 files changed, 79 insertions(+), 2 deletions(-)
 create mode 100644 tools/extractor/BUILD.bazel
 create mode 100644 tools/extractor/main.go

diff --git a/beacon-chain/core/state/interop/BUILD.bazel b/beacon-chain/core/state/interop/BUILD.bazel
index a403ff9e90..189fb9ed65 100644
--- a/beacon-chain/core/state/interop/BUILD.bazel
+++ b/beacon-chain/core/state/interop/BUILD.bazel
@@ -8,7 +8,10 @@ go_library(
         "write_state_to_disk.go",
     ],
     importpath = "github.com/prysmaticlabs/prysm/beacon-chain/core/state/interop",
-    visibility = ["//beacon-chain:__subpackages__"],
+    visibility = [
+        "//beacon-chain:__subpackages__",
+        "//tools:__subpackages__",
+    ],
     deps = [
         "//proto/beacon/p2p/v1:go_default_library",
         "//proto/eth/v1alpha1:go_default_library",
diff --git a/beacon-chain/db/filters/BUILD.bazel b/beacon-chain/db/filters/BUILD.bazel
index 5d9c824206..d638212d9b 100644
--- a/beacon-chain/db/filters/BUILD.bazel
+++ b/beacon-chain/db/filters/BUILD.bazel
@@ -4,7 +4,10 @@ go_library(
     name = "go_default_library",
     srcs = ["filter.go"],
     importpath = "github.com/prysmaticlabs/prysm/beacon-chain/db/filters",
-    visibility = ["//beacon-chain:__subpackages__"],
+    visibility = [
+        "//beacon-chain:__subpackages__",
+        "//tools:__subpackages__",
+    ],
 )
 
 go_test(
diff --git a/tools/extractor/BUILD.bazel b/tools/extractor/BUILD.bazel
new file mode 100644
index 0000000000..0a838619bb
--- /dev/null
+++ b/tools/extractor/BUILD.bazel
@@ -0,0 +1,20 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["main.go"],
+    importpath = "github.com/prysmaticlabs/prysm/tools/extractor",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//beacon-chain/core/state/interop:go_default_library",
+        "//beacon-chain/db:go_default_library",
+        "//beacon-chain/db/filters:go_default_library",
+        "//shared/featureconfig:go_default_library",
+    ],
+)
+
+go_binary(
+    name = "extractor",
+    embed = [":go_default_library"],
+    visibility = ["//visibility:public"],
+)
diff --git a/tools/extractor/main.go b/tools/extractor/main.go
new file mode 100644
index 0000000000..8dcec7a64c
--- /dev/null
+++ b/tools/extractor/main.go
@@ -0,0 +1,51 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/state/interop"
+	"github.com/prysmaticlabs/prysm/beacon-chain/db"
+	"github.com/prysmaticlabs/prysm/beacon-chain/db/filters"
+	"github.com/prysmaticlabs/prysm/shared/featureconfig"
+)
+
+var (
+	// Required fields
+	datadir = flag.String("datadir", "", "Path to data directory.")
+
+	state = flag.Uint("state", 0, "Extract state at this slot.")
+
+)
+
+func init() {
+	fc := featureconfig.Get()
+	fc.WriteSSZStateTransitions = true
+	featureconfig.Init(fc)
+}
+
+func main() {
+	flag.Parse()
+	fmt.Println("Starting process...")
+	d, err := db.NewDB(*datadir)
+	if err != nil {
+		panic(err)
+	}
+	ctx := context.Background()
+	slot := uint64(*state)
+	roots, err := d.BlockRoots(ctx, filters.NewFilter().SetStartSlot(slot).SetEndSlot(slot))
+	if err != nil {
+		panic(err)
+	}
+	if len(roots) != 1 {
+		fmt.Printf("Expected 1 block root for slot %d, got %d roots", *state, len(roots))
+	}
+	s, err := d.State(ctx, roots[0])
+	if err != nil {
+		panic(err)
+	}
+
+	interop.WriteStateToDisk(s)
+	fmt.Println("done")
+}