From 08e05398069bb8e480c7a0a4d0b4630f89cb3157 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Igor=20Anic=CC=81?= <igor.anic@gmail.com>
Date: Sat, 20 Jan 2024 22:45:40 +0100
Subject: [PATCH] add more cases to the deflate benchmark

---
 bin/deflate_bench.zig | 33 ++++++++++++++++++++++++++-------
 bin/gzip.zig          | 22 ++++++++++++++++++++++
 build.zig             | 26 ++++++++++++++++++--------
 src/deflate.zig       |  2 +-
 4 files changed, 67 insertions(+), 16 deletions(-)
 create mode 100644 bin/gzip.zig

diff --git a/bin/deflate_bench.zig b/bin/deflate_bench.zig
index 9df095b..5b7f2a3 100644
--- a/bin/deflate_bench.zig
+++ b/bin/deflate_bench.zig
@@ -1,8 +1,8 @@
 const std = @import("std");
 const flate = @import("flate");
 
+//const data = @embedFile("benchdata/large.tar");
 //const data = @embedFile("benchdata/2600.txt.utf-8");
-
 const data = @embedFile("benchdata/bb0f7d55e8c50e379fa9bdcb8758d89d08e0cc1f.tar");
 
 pub fn main() !void {
@@ -11,15 +11,19 @@ pub fn main() !void {
     const arena_allocator = arena.allocator();
     const args = try std.process.argsAlloc(arena_allocator);
 
-    const output_file_name = "output.gz";
-    var output_file = try std.fs.cwd().createFile(output_file_name, .{ .truncate = true });
-    const output = output_file.writer();
-    defer output_file.close();
+    // const output_file_name = "output.zz";
+    // var output_file = try std.fs.cwd().createFile(output_file_name, .{ .truncate = true });
+    // const output = output_file.writer();
+    // defer output_file.close();
+
+    //const output = std.io.getStdOut().writer();
+
+    const output = NullWriter.init().writer();
 
     var i: usize = 1;
     while (i < args.len) : (i += 1) {
         if (std.mem.eql(u8, args[i], "--std")) {
-            //try stdZlib(output);
+            try stdZlib(output);
             return;
         } else {
             std.os.exit(1);
@@ -35,9 +39,24 @@ pub fn lib(output: anytype) !void {
 
 pub fn stdZlib(writer: anytype) !void {
     const allocator = std.heap.page_allocator;
-    var compressor = try std.compress.zlib.compressStream(allocator, writer, .{});
+    var compressor = try std.compress.zlib.compressStream(allocator, writer, .{ .level = .default });
     defer compressor.deinit();
 
     try compressor.writer().writeAll(data);
     try compressor.finish();
 }
+
+const NullWriter = struct {
+    const Self = @This();
+    pub const WriteError = error{};
+    pub const Writer = std.io.Writer(Self, WriteError, write);
+    pub fn writer(self: Self) Writer {
+        return .{ .context = self };
+    }
+    pub fn write(_: Self, bytes: []const u8) WriteError!usize {
+        return bytes.len;
+    }
+    pub fn init() Self {
+        return .{};
+    }
+};
diff --git a/bin/gzip.zig b/bin/gzip.zig
new file mode 100644
index 0000000..e869a64
--- /dev/null
+++ b/bin/gzip.zig
@@ -0,0 +1,22 @@
+const std = @import("std");
+const flate = @import("flate");
+
+// Comparable to standard gzip with -kf flags:
+// $ gzip -kf <file_name>
+//
+pub fn main() !void {
+    var args = std.process.args();
+    _ = args.next();
+
+    if (args.next()) |input_file_name| {
+        var input_file = try std.fs.cwd().openFile(input_file_name, .{});
+        defer input_file.close();
+
+        var buf: [std.fs.MAX_PATH_BYTES]u8 = undefined;
+        const output_file_name = try std.fmt.bufPrint(&buf, "{s}.gz", .{input_file_name});
+        var output_file = try std.fs.cwd().createFile(output_file_name, .{ .truncate = true });
+        defer output_file.close();
+
+        try flate.gzip(input_file.reader(), output_file.writer());
+    }
+}
diff --git a/build.zig b/build.zig
index 240a311..599be9b 100644
--- a/build.zig
+++ b/build.zig
@@ -98,12 +98,22 @@ pub fn build(b: *std.Build) void {
         .source_file = .{ .path = "src/root.zig" },
     });
 
-    const gzip_bench = b.addExecutable(.{
-        .name = "deflate_bench",
-        .root_source_file = .{ .path = "bin/deflate_bench.zig" },
-        .target = target,
-        .optimize = optimize,
-    });
-    gzip_bench.addModule("flate", flate_module);
-    b.installArtifact(gzip_bench);
+    const bins = [_]struct {
+        name: []const u8,
+        src: []const u8,
+    }{
+        .{ .name = "deflate_bench", .src = "bin/deflate_bench.zig" },
+        .{ .name = "gzip", .src = "bin/gzip.zig" },
+    };
+
+    for (bins) |i| {
+        const bin = b.addExecutable(.{
+            .name = i.name,
+            .root_source_file = .{ .path = i.src },
+            .target = target,
+            .optimize = optimize,
+        });
+        bin.addModule("flate", flate_module);
+        b.installArtifact(bin);
+    }
 }
diff --git a/src/deflate.zig b/src/deflate.zig
index ca79f64..f1eef3b 100644
--- a/src/deflate.zig
+++ b/src/deflate.zig
@@ -431,7 +431,7 @@ const Lookup = struct {
     }
 
     // Previous location with the same hash value.
-    pub fn prev(self: *Lookup, idx: u32) u32 {
+    pub inline fn prev(self: *Lookup, idx: u32) u32 {
         const v = self.chain[idx & mask];
         return if (v > idx) not_found else v;
     }