Update main.zig

main.zig

@@ -1,13 +1,43 @@
 // using zig-0.15.2
 const std = @import("std");
+const sha256 = std.crypto.hash.sha2.Sha256;
+const stdout = std.fs.File.stdout();
+const stderr = std.fs.File.stderr();
+
+fn err_print(comptime fmt: []const u8, args: anytype) void {
+    var writer = stderr.writer(&.{});
+    writer.interface.print(fmt, args) catch unreachable;
+}
+
+fn out_print(comptime fmt: []const u8, args: anytype) void {
+    var writer = stdout.writer(&.{});
+    writer.interface.print(fmt, args) catch unreachable;
+}
 
 const File = struct {
-    path: [:0]u8,
+    path: []u8,
     size: u64,
-    duplicate_size: ?usize = null,
+    solved: bool = false,
     hash: ?u256 = null,
 };
 
+var hashcount: usize = 0;
+
+fn hashFile(f: std.fs.File, allocator: std.mem.Allocator) !u256 {
+    hashcount += 1;
+    var buf: [1024 * 32]u8 = undefined;
+    var reader = f.reader(&buf);
+    const file_contents = try reader.interface.allocRemaining(allocator, .unlimited);
+    defer allocator.free(file_contents);
+    var hash_buff: [sha256.digest_length]u8 = undefined;
+    sha256.hash(file_contents, &hash_buff, .{});
+    return std.mem.bytesToValue(u256, &hash_buff);
+}
+
+fn cmp_fn(_: u8, lhs: File, rhs: File) bool {
+    return lhs.size < rhs.size;
+}
+
 pub fn main() !void {
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
     const allocator = gpa.allocator();
@@ -17,29 +47,80 @@ pub fn main() !void {
     defer list.deinit(allocator);
     var args_it = std.process.args();
     _ = args_it.next(); // skip program name
+
+    var file_count: usize = 0;
+    const start_time = try std.time.Instant.now();
+
     while (args_it.next()) |arg| {
         const dir = try std.fs.cwd().openDir(arg, .{ .iterate = true });
         var walker = try dir.walk(allocator);
         defer walker.deinit();
         while (try walker.next()) |entry| {
             if (entry.kind == .file) {
+                file_count += 1;
                 const stat = try entry.dir.statFile(entry.basename);
+                const path = try entry.dir.realpathAlloc(allocator, entry.basename);
                 try list.append(allocator, .{
-                    .path = try allocator.dupeZ(u8, entry.path),
+                    .path = path,
                     .size = stat.size,
                 });
             }
         }
     }
 
+    std.mem.sort(File, list.items, @as(u8, 0), cmp_fn);
+    for (list.items) |*item| {
+        err_print("file: {any}\n", .{item.size});
+    }
+
     for (list.items, 0..) |*item, idx| {
-        for (list.items) |*item2| {
+        if (item.solved) continue;
+        var duplicates: std.ArrayList(usize) = .empty;
+        defer duplicates.deinit(allocator);
+        for (list.items, 0..) |*item2, idx2| {
+            if (item2.solved) continue;
+            if (std.mem.eql(u8, item.path, item2.path)) continue;
+
             if (item.size == item2.size) {
-                item.duplicate_size = idx;
-                item2.duplicate_size = idx;
+                if (item.hash == null) {
+                    const file = try std.fs.openFileAbsolute(item.path, .{});
+                    defer file.close();
+                    item.hash = try hashFile(file, allocator);
+                }
+                if (item2.hash == null) {
+                    const file = try std.fs.openFileAbsolute(item2.path, .{});
+                    defer file.close();
+                    item2.hash = try hashFile(file, allocator);
+                }
+                if (item.hash.? == item2.hash.?) {
+                    if (duplicates.items.len == 0) {
+                        try duplicates.append(allocator, idx);
+                        item.solved = true;
+                    }
+                    try duplicates.append(allocator, idx2);
+                    item2.solved = true;
                 }
             }
-        std.debug.print("path: {s}, size {}\n", .{ item.path, item.size });
+        }
+        if (duplicates.items.len > 0) {
+            for (duplicates.items, 0..) |dup_idx, i| {
+                if (i == 0) {
+                    out_print("duplicate ({}): \n    {s}\n", .{ duplicates.items.len, list.items[duplicates.items[0]].path });
+                } else if (i == duplicates.items.len - 1) {
+                    out_print("    {s}\n", .{list.items[dup_idx].path});
+                } else {
+                    out_print("    {s}\n", .{list.items[dup_idx].path});
+                }
+            }
+        }
+    }
+
+    for (list.items) |*item| {
         allocator.free(item.path);
     }
+
+    const end_time = try std.time.Instant.now();
+    const elapsed_nanos = end_time.since(start_time);
+    const elapsed_seconds = @as(f64, @floatFromInt(elapsed_nanos)) / std.time.ns_per_s;
+    err_print("found {} files in {:.2}s and hashcount is {}\n", .{ file_count, elapsed_seconds, hashcount });
 }