add bench/twitter

in an attempt to verify benchmarks, the new cpp and zig files now loop
over statuses in twitter.json and check that there are exactly 100.

running bench/twitter/run.sh
  * builds zig-out/bin/twitterbench
  * fetches simdjson.cpp/.h and twitter.json
  * builds bench/twitter/simdjzon-twitterbench
  * benchmarks them w/ poop

bench/twitter/.gitignore

@@ -0,0 +1,4 @@
+simdjson-twitterbench
+simdjson.cpp
+simdjson.h
+twitter.json

bench/twitter/main.cpp

@@ -0,0 +1,28 @@
+#include "simdjson.h"
+using namespace simdjson;
+int main(int argc, char** argv) {
+    if(argc != 2) {
+        std::cout << "USAGE: ./simdjson <file.json>" << std::endl;
+        exit(1);
+    }
+    dom::parser parser; 
+    try
+    {
+        const dom::element doc = parser.load(argv[1]);
+        int i = 0;
+        for(auto status: doc["statuses"]) {
+            // std::cout << status["id"] << '\n';
+            i += 1;
+        }
+        if(i != 100) {
+            std::cout << "error. expected i=100. found i=" << i << '\n';
+            return 1;
+        }
+    }
+    catch(const std::exception& e)
+    {
+        std::cerr << e.what() << '\n';
+        return 1;
+    }
+    return 0;
+}

bench/twitter/main.zig

@@ -0,0 +1,33 @@
+const std = @import("std");
+const dom = @import("simdjzon").dom;
+
+pub fn main() !u8 {
+    var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
+    defer arena.deinit();
+    const allocator = arena.allocator();
+    const args = try std.process.argsAlloc(allocator);
+    if(args.len != 2) {
+      std.debug.print("USAGE: ./simdjson <file.json>\n", .{});
+    }
+    var parser = try dom.Parser.initFile(allocator, args[1], .{});
+    defer parser.deinit();
+    parser.parse() catch |err| {
+        std.log.err("parse failed. {s}", .{@errorName(err)});
+        return 1;
+    };
+    const statuses = try parser.element().at_pointer("/statuses");
+    const array = try statuses.get_array();
+    var i: usize = 0;
+    while(array.at(i)) |status| : (i += 1) {
+        _ = status; // autofix
+      // const id = try status.at_pointer("/id");      
+      // std.debug.print("{}\n", .{try id.get_int64()});
+    }
+    // std.debug.print("i={}\n", .{i});
+    if (i != 100) {
+      std.debug.print("error. expected i=100. found i={}\n", .{i});
+      return 1;
+    }
+
+    return 0;
+}

bench/twitter/run.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+set -xe
+
+rm -f simdjson.cpp simdjson.h twitter.json simdjson-twitterbench
+
+# build simdjzon
+zig version
+zig build -Doptimize=ReleaseFast
+
+# build simdjson
+g++ --version
+cat bench/twitter/main.cpp
+wget https://github.com/simdjson/simdjson/raw/master/singleheader/simdjson.cpp -O bench/twitter/simdjson.cpp
+wget https://github.com/simdjson/simdjson/raw/master/singleheader/simdjson.h -O bench/twitter/simdjson.h
+wget https://github.com/simdjson/simdjson/raw/master/jsonexamples/twitter.json -O bench/twitter/twitter.json
+g++ bench/twitter/main.cpp bench/twitter/simdjson.cpp -Ibench/twitter -o bench/twitter/simdjson-twitterbench -O3 -march=native
+
+# bench
+poop "./bench/twitter/simdjson-twitterbench bench/twitter/twitter.json" "zig-out/bin/twitterbench bench/twitter/twitter.json"

build.zig

@@ -71,4 +71,18 @@ pub fn build(b: *std.Build) void {
 
     const run_step = b.step("run", "Run the app");
     run_step.dependOn(&run_cmd.step);
+
+    const twitterbench = b.addExecutable(.{
+        .name = "twitterbench",
+        .root_source_file = .{ .path = "bench/twitter/main.zig" },
+        .target = target,
+        .optimize = optimize,
+    });
+    twitterbench.root_module.addImport("simdjzon", mod);
+    b.installArtifact(twitterbench);
+    const run_twitter_bench = b.addRunArtifact(twitterbench);
+    if (b.args) |args| run_twitter_bench.addArgs(args);
+    const run_twitter_bench_step = b.step("twitter-bench", "Run the twitter-bench");
+    run_twitter_bench_step.dependOn(&run_twitter_bench.step);
+
 }