asimview: add sha comparison functionality

pkg/BUILD.bazel

@@ -1505,6 +1505,8 @@ GO_TARGETS = [
     "//pkg/kv/kvserver/asim/state:state_test",
     "//pkg/kv/kvserver/asim/storerebalancer:storerebalancer",
     "//pkg/kv/kvserver/asim/storerebalancer:storerebalancer_test",
+    "//pkg/kv/kvserver/asim/tests/cmd/asimview:asimview",
+    "//pkg/kv/kvserver/asim/tests/cmd/asimview:asimview_lib",
     "//pkg/kv/kvserver/asim/tests:tests",
     "//pkg/kv/kvserver/asim/tests:tests_test",
     "//pkg/kv/kvserver/asim/workload:workload",

pkg/kv/kvserver/asim/tests/cmd/asimview/BUILD.bazel

@@ -0,0 +1,22 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+
+go_library(
+    name = "asimview_lib",
+    srcs = [
+        "main.go",
+        "sha_compare.go",
+    ],
+    embedsrcs = [
+        "mma.png",
+        "sha_compare.html",
+        "viewer.html",
+    ],
+    importpath = "github.com/cockroachdb/cockroach/pkg/kv/kvserver/asim/tests/cmd/asimview",
+    visibility = ["//visibility:private"],
+)
+
+go_binary(
+    name = "asimview",
+    embed = [":asimview_lib"],
+    visibility = ["//visibility:public"],
+)

pkg/kv/kvserver/asim/tests/cmd/asimview/README.md

@@ -0,0 +1,47 @@
+# ASIM Test Results Viewer
+
+Interactive web viewer for ASIM test JSON output files with fuzzy search and multi-file comparison.
+
+## Usage
+
+### Regular File Viewer Mode
+
+```bash
+# Default: serves files from repo's testdata/generated directory
+go run .
+
+# Or specify a custom directory
+go run . /path/to/json/files
+
+# Custom port
+go run . -port 8081
+```
+
+Then open http://localhost:8080 in your browser.
+
+### SHA Comparison Mode
+
+```bash
+# Enable SHA comparison mode
+go run . -sha-compare
+
+# With custom port
+go run . -sha-compare -port 8081
+```
+
+Then open http://localhost:8080 in your browser. This mode allows you to:
+
+1. **Generate test data for different Git SHAs**: Enter two commit SHAs and click "Generate Comparison" to run ASIM tests for both commits
+2. **Compare results side-by-side**: Select test files to see JSON data plotted side-by-side for visual comparison
+3. **Automatic Git workflow**: The tool handles switching between SHAs, running tests, and storing results automatically
+
+**Note**: SHA comparison mode requires a clean Git working directory and will temporarily switch between commits to generate test data.
+
+## Features
+
+- **Fuzzy Search**: Type any part of test name or file name to filter
+- **Multiple Selection**: Select multiple test files to compare side-by-side
+- **Synchronized Zoom**: Drag to zoom on any chart, all charts sync automatically
+- **Copy Data**: Click the clipboard button on any chart to copy its timeseries data as JSON
+- **Auto-discovery**: Recursively finds all JSON files in the specified directory
+- **Local Storage**: Remembers your last selection and zoom state. (Can refresh the browser window to update loaded files).