tiny.smg.cli.subgraph

1pub const subgraph = @import("subgraph.zig");

1const std = @import("std");23const smg = @import("../root.zig");4const graph_mod = smg.graph;5const model = smg.model;6const table = smg.cli.table;7const view = smg.view;89pub fn writeSummary(allocator: std.mem.Allocator, writer: *std.Io.Writer, graph: graph_mod.Graph, name: []const u8, depth: i64, limit: i64) !void {10    const nodes = try view.allNodes(graph, allocator, null);11    const edges = try view.allEdges(graph, allocator);12    const degrees = try subgraphDegrees(allocator, graph);13    const displayed = if (limit <= 0 or @as(u64, @intCast(limit)) > @as(u64, @intCast(degrees.len))) degrees.len else @as(usize, @intCast(limit));14    try writer.print("Subgraph of {s} (depth={d})\n", .{ name, depth });15    try writer.print("  {d} nodes, {d} edges\n\n", .{ nodes.len, edges.len });16    const columns = [_]table.Column{17        .{ .header = "type", .max_width = 14 },18        .{ .header = "name", .max_width = 56 },19        .{ .header = "edges", .alignment = .right, .max_width = 8 },20    };21    var scratch_state = std.heap.ArenaAllocator.init(allocator);22    defer scratch_state.deinit();23    const scratch = scratch_state.allocator();24    var rows: std.ArrayList([]const []const u8) = .empty;25    for (degrees[0..displayed]) |row| {26        try table.appendRow(scratch, &rows, &.{27            row.type,28            row.name,29            try std.fmt.allocPrint(scratch, "{d}", .{row.degree}),30        });31    }32    try table.writeJsonOption(allocator, writer, &columns, rows.items, degrees.len, "--format json");33}3435pub fn prune(allocator: std.mem.Allocator, graph: graph_mod.Graph, limit: usize) !graph_mod.Graph {36    const degrees = try subgraphDegrees(allocator, graph);37    var keep = std.StringHashMap(void).init(allocator);38    var out = graph_mod.init(allocator);39    const displayed = @min(limit, degrees.len);40    for (degrees[0..displayed]) |row| {41        try keep.put(row.name, {});42        if (graph_mod.getNode(&graph, row.name)) |node| try graph_mod.addNode(&out, node);43    }44    for (try view.allEdges(graph, allocator)) |edge| {45        if (keep.contains(edge.source) and keep.contains(edge.target)) try graph_mod.addEdge(&out, edge);46    }47    return out;48}4950const DegreeRow = struct {51    name: []const u8,52    type: []const u8,53    degree: usize,54};5556fn subgraphDegrees(allocator: std.mem.Allocator, graph: graph_mod.Graph) ![]const DegreeRow {57    var rows: std.ArrayList(DegreeRow) = .empty;58    for (try view.allNodes(graph, allocator, null)) |node| {59        const incoming = try view.incoming(graph, allocator, node.name, null);60        const outgoing = try view.outgoing(graph, allocator, node.name, null);61        try rows.append(allocator, .{ .name = node.name, .type = node.type, .degree = incoming.len + outgoing.len });62    }63    std.mem.sort(DegreeRow, rows.items, {}, degreeRowLess);64    return try rows.toOwnedSlice(allocator);65}6667fn degreeRowLess(_: void, a: DegreeRow, b: DegreeRow) bool {68    if (a.degree != b.degree) return a.degree > b.degree;69    return std.mem.lessThan(u8, a.name, b.name);70}7172test "subgraph summary renders degree ranked python shape" {73    var arena = std.heap.ArenaAllocator.init(std.testing.allocator);74    defer arena.deinit();75    const allocator = arena.allocator();76    var graph = graph_mod.init(allocator);77    for ([_][]const u8{ "app", "app.main", "app.helper", "lib", "lib.util" }) |name| {78        try graph_mod.addNode(&graph, .{ .name = name, .type = if (std.mem.indexOfScalar(u8, name, '.')) |_| model.NodeType.function else model.NodeType.module });79    }80    try graph_mod.addEdge(&graph, .{ .source = "app", .rel = model.RelType.contains, .target = "app.main" });81    try graph_mod.addEdge(&graph, .{ .source = "app", .rel = model.RelType.contains, .target = "app.helper" });82    try graph_mod.addEdge(&graph, .{ .source = "app.main", .rel = model.RelType.calls, .target = "app.helper" });83    try graph_mod.addEdge(&graph, .{ .source = "app.helper", .rel = model.RelType.imports, .target = "lib.util" });84    try graph_mod.addEdge(&graph, .{ .source = "lib", .rel = model.RelType.contains, .target = "lib.util" });85    var out: std.Io.Writer.Allocating = .init(allocator);86    try writeSummary(allocator, &out.writer, graph, "app.helper", 2, 2);87    try std.testing.expectEqualStrings(88        "Subgraph of app.helper (depth=2)\n" ++89            "  5 nodes, 5 edges\n" ++90            "\n" ++91            "type      name        edges\n" ++92            "--------  ----------  -----\n" ++93            "function  app.helper      3\n" ++94            "module    app             2\n" ++95            "(showing 2 of 5 \xE2\x80\x94 use --limit 0 for all, --format json for exact records)\n",96        out.written(),97    );98}