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Nathan Fisher 2024-06-01 18:47:22 -04:00
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zig-out/
zig-cache/

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const std = @import("std");
// Although this function looks imperative, note that its job is to
// declaratively construct a build graph that will be executed by an external
// runner.
pub fn build(b: *std.Build) void {
// Standard target options allows the person running `zig build` to choose
// what target to build for. Here we do not override the defaults, which
// means any target is allowed, and the default is native. Other options
// for restricting supported target set are available.
const target = b.standardTargetOptions(.{});
// Standard optimization options allow the person running `zig build` to select
// between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
// set a preferred release mode, allowing the user to decide how to optimize.
const optimize = b.standardOptimizeOption(.{});
const lib = b.addStaticLibrary(.{
.name = "b64_zig",
// In this case the main source file is merely a path, however, in more
// complicated build scripts, this could be a generated file.
.root_source_file = b.path("src/root.zig"),
.target = target,
.optimize = optimize,
});
// This declares intent for the library to be installed into the standard
// location when the user invokes the "install" step (the default step when
// running `zig build`).
b.installArtifact(lib);
const exe = b.addExecutable(.{
.name = "b64_zig",
.root_source_file = b.path("src/main.zig"),
.target = target,
.optimize = optimize,
});
// This declares intent for the executable to be installed into the
// standard location when the user invokes the "install" step (the default
// step when running `zig build`).
b.installArtifact(exe);
// This *creates* a Run step in the build graph, to be executed when another
// step is evaluated that depends on it. The next line below will establish
// such a dependency.
const run_cmd = b.addRunArtifact(exe);
// By making the run step depend on the install step, it will be run from the
// installation directory rather than directly from within the cache directory.
// This is not necessary, however, if the application depends on other installed
// files, this ensures they will be present and in the expected location.
run_cmd.step.dependOn(b.getInstallStep());
// This allows the user to pass arguments to the application in the build
// command itself, like this: `zig build run -- arg1 arg2 etc`
if (b.args) |args| {
run_cmd.addArgs(args);
}
// This creates a build step. It will be visible in the `zig build --help` menu,
// and can be selected like this: `zig build run`
// This will evaluate the `run` step rather than the default, which is "install".
const run_step = b.step("run", "Run the app");
run_step.dependOn(&run_cmd.step);
// Creates a step for unit testing. This only builds the test executable
// but does not run it.
const lib_unit_tests = b.addTest(.{
.root_source_file = b.path("src/root.zig"),
.target = target,
.optimize = optimize,
});
const run_lib_unit_tests = b.addRunArtifact(lib_unit_tests);
const exe_unit_tests = b.addTest(.{
.root_source_file = b.path("src/main.zig"),
.target = target,
.optimize = optimize,
});
const run_exe_unit_tests = b.addRunArtifact(exe_unit_tests);
// Similar to creating the run step earlier, this exposes a `test` step to
// the `zig build --help` menu, providing a way for the user to request
// running the unit tests.
const test_step = b.step("test", "Run unit tests");
test_step.dependOn(&run_lib_unit_tests.step);
test_step.dependOn(&run_exe_unit_tests.step);
}

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.{
.name = "b64_zig",
// This is a [Semantic Version](https://semver.org/).
// In a future version of Zig it will be used for package deduplication.
.version = "0.0.0",
// This field is optional.
// This is currently advisory only; Zig does not yet do anything
// with this value.
//.minimum_zig_version = "0.11.0",
// This field is optional.
// Each dependency must either provide a `url` and `hash`, or a `path`.
// `zig build --fetch` can be used to fetch all dependencies of a package, recursively.
// Once all dependencies are fetched, `zig build` no longer requires
// internet connectivity.
.dependencies = .{
// See `zig fetch --save <url>` for a command-line interface for adding dependencies.
//.example = .{
// // When updating this field to a new URL, be sure to delete the corresponding
// // `hash`, otherwise you are communicating that you expect to find the old hash at
// // the new URL.
// .url = "https://example.com/foo.tar.gz",
//
// // This is computed from the file contents of the directory of files that is
// // obtained after fetching `url` and applying the inclusion rules given by
// // `paths`.
// //
// // This field is the source of truth; packages do not come from a `url`; they
// // come from a `hash`. `url` is just one of many possible mirrors for how to
// // obtain a package matching this `hash`.
// //
// // Uses the [multihash](https://multiformats.io/multihash/) format.
// .hash = "...",
//
// // When this is provided, the package is found in a directory relative to the
// // build root. In this case the package's hash is irrelevant and therefore not
// // computed. This field and `url` are mutually exclusive.
// .path = "foo",
// // When this is set to `true`, a package is declared to be lazily
// // fetched. This makes the dependency only get fetched if it is
// // actually used.
// .lazy = false,
//},
},
// Specifies the set of files and directories that are included in this package.
// Only files and directories listed here are included in the `hash` that
// is computed for this package.
// Paths are relative to the build root. Use the empty string (`""`) to refer to
// the build root itself.
// A directory listed here means that all files within, recursively, are included.
.paths = .{
// This makes *all* files, recursively, included in this package. It is generally
// better to explicitly list the files and directories instead, to insure that
// fetching from tarballs, file system paths, and version control all result
// in the same contents hash.
"",
// For example...
//"build.zig",
//"build.zig.zon",
//"src",
//"LICENSE",
//"README.md",
},
}

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const std = @import("std");
pub fn main() !void {
// Prints to stderr (it's a shortcut based on `std.io.getStdErr()`)
std.debug.print("All your {s} are belong to us.\n", .{"codebase"});
// stdout is for the actual output of your application, for example if you
// are implementing gzip, then only the compressed bytes should be sent to
// stdout, not any debugging messages.
const stdout_file = std.io.getStdOut().writer();
var bw = std.io.bufferedWriter(stdout_file);
const stdout = bw.writer();
try stdout.print("Run `zig build test` to run the tests.\n", .{});
try bw.flush(); // don't forget to flush!
}
test "simple test" {
var list = std.ArrayList(i32).init(std.testing.allocator);
defer list.deinit(); // try commenting this out and see if zig detects the memory leak!
try list.append(42);
try std.testing.expectEqual(@as(i32, 42), list.pop());
}

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const std = @import("std");
const testing = std.testing;
const GenericReader = std.io.GenericReader;
const GenericWriter = std.io.GenericWriter;
const b64Error = error{
InvalidChar,
MissingPad,
};
pub const b64Alphabet = struct {
chars: [64]u8,
pad: u8,
const Self = @This();
fn getIdx(self: Self, c: u8) b64Error!u6 {
for (self.chars, 0..64) |b, i| {
if (c == b) {
return @intCast(i);
}
}
return b64Error.InvalidChar;
}
fn getchar(self: Self, idx: u6) u8 {
return self.chars[idx];
}
fn encodeChunk(self: Self, chunk: [3]u8, len: usize, out: *[4]u8) [4]u8 {
var num: u24 = 0;
var outbuf = out.*;
inline for (0..3) |i| {
outbuf[i] = self.pad;
}
for (0..3) |i| {
num <<= 8;
if (len > i) {
num |= chunk[i];
}
}
var n: u6 = 0;
var idx: usize = 4;
var outlen = len * 8 / 6;
if (len * 8 % 6 > 0) outlen += 1;
while (idx > 0) : ({
idx -= 1;
num >>= 6;
}) {
if (idx <= outlen) {
n = @truncate(num & 0x3f);
outbuf[idx - 1] = self.chars[n];
} else {
outbuf[idx - 1] = self.pad;
}
}
return outbuf;
}
/// Encodes a twelve element array of bytes and returns a sixteen element
/// array encoded in base64. This function uses simd instructions to run
/// the bitwise operations required for encoding using four parallel vectors
/// of bytes.
fn encodeChunksVectored(self: Self, in: [12]u8, out: *[16]u8) [16]u8 {
var outbuf = out.*;
var numvec: @Vector(4, u24) = @splat(0);
const shlvec: @Vector(4, usize) = @splat(8);
for (0..3) |i| {
numvec <<= shlvec;
const invec = @Vector(4, u8){ in[i], in[i + 3], in[i + 6], in[i + 9] };
numvec |= invec;
}
const maskvec: @Vector(4, u6) = @splat(0x3f);
var idx: usize = 4;
const shrvec: @Vector(4, u8) = @splat(6);
while (idx > 0) : ({
idx -= 1;
numvec >>= shrvec;
}) {
const idxvec = numvec & maskvec;
outbuf[idx - 1] = self.chars[idxvec[0]];
outbuf[idx + 3] = self.chars[idxvec[1]];
outbuf[idx + 7] = self.chars[idxvec[2]];
outbuf[idx + 11] = self.chars[idxvec[3]];
}
return outbuf;
}
fn decodeChunk(self: Self, chunk: [4]u8, out: *[3]u8) b64Error![3]u8 {
var num: u24 = 0;
var outbuf = out.*;
var len: usize = 0;
for (chunk) |c| {
num <<= 6;
if (self.getIdx(c)) |idx| {
num |= idx;
} else |err| {
if (c != self.pad) return err;
}
len += 1;
}
var i: usize = 3;
var outlen = len * 6 / 8;
if (len * 6 % 8 != 0) outlen += 1;
while (i > 0) : ({
i -= 1;
num >>= 8;
}) {
outbuf[i - 1] = if (i <= outlen) @intCast(num & 0xff) else 0;
}
return outbuf;
}
fn decodeChunksVectored(self: Self, in: [16]u8, out: *[12]u8) ![12]u8 {
var outbuf = out.*;
var numvec: @Vector(4, u24) = @splat(0);
const shlvec: @Vector(4, usize) = @splat(6);
for (0..4) |i| {
numvec <<= shlvec;
var inarr: [4]u6 = undefined;
inarr[0] = try self.getIdx(i);
inarr[1] = try self.getIdx(in[i + 4]);
inarr[2] = try self.getIdx(in[i + 8]);
inarr[3] = try self.getIdx(in[i + 12]);
const invec: @Vector(4, u6) = inarr;
numvec |= invec;
}
const maskvec: @Vector(4, u8) = @splat(0xff);
const shrvec: @Vector(4, u8) = @splat(8);
var idx: usize = 3;
while (idx > 0) : ({
idx -= 1;
numvec >>= shrvec;
}) {
const cvec = numvec & maskvec;
outbuf[idx - 1] = cvec[0];
outbuf[idx + 2] = cvec[1];
outbuf[idx + 5] = cvec[2];
outbuf[idx + 8] = cvec[3];
}
return outbuf;
}
};
pub const rfc4648B64Alphabet = b64Alphabet{
.chars = [64]u8{ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' },
.pad = '=',
};
test "alphabet getIdx" {
try testing.expect(try rfc4648B64Alphabet.getIdx('a') == 26);
try testing.expect(try rfc4648B64Alphabet.getIdx('+') == 62);
}
test "alphabet getChar" {
try testing.expect(rfc4648B64Alphabet.getchar(4) == 'E');
}
test "encode chunk" {
const chunk = [3]u8{ 'H', 'e', 'l' };
var out: [4]u8 = undefined;
const obuf = rfc4648B64Alphabet.encodeChunk(chunk, 3, &out);
try testing.expect(std.mem.eql(u8, obuf[0..], "SGVs"));
}
test "encode chunk 2long" {
const chunk = [3]u8{ 'H', 'e', 0 };
var out: [4]u8 = undefined;
const obuf = rfc4648B64Alphabet.encodeChunk(chunk, 2, &out);
try testing.expect(std.mem.eql(u8, obuf[0..], "SGU="));
}
test "encode chunks vectored" {
const chunk = [12]u8{ 'H', 'e', 'l', 'l', 'o', ',', ' ', 'W', 'o', 'r', 'l', 'd' };
var out: [16]u8 = undefined;
const obuf = rfc4648B64Alphabet.encodeChunksVectored(chunk, &out);
try testing.expect(std.mem.eql(u8, obuf[0..], "SGVsbG8sIFdvcmxk"));
}
test "decode chunk" {
const chunk = [4]u8{ 'S', 'G', 'V', 's' };
var out: [3]u8 = undefined;
const obuf = try rfc4648B64Alphabet.decodeChunk(chunk, &out);
try testing.expect(std.mem.eql(u8, obuf[0..], "Hel"));
}
pub const b64Encoder = struct {
reader: GenericReader,
writer: GenericWriter,
alphabet: b64Alphabet,
const Self = @This();
pub fn init(reader: GenericReader, writer: GenericWriter, alphabet: ?b64Alphabet) Self {
return Self{
.reader = reader,
.writer = writer,
.alphabet = if (alphabet) |a| a else rfc4648B64Alphabet,
};
}
pub fn encode(self: Self) !void {
_ = self;
// todo
}
};
pub const b64Decoder = struct {
reader: std.io.GenericReader,
writer: std.io.GenericWriter,
alphabet: b64Alphabet,
const Self = @This();
pub fn init(reader: GenericReader, writer: GenericWriter, alphabet: b64Alphabet) Self {
return Self{
.reader = reader,
.writer = writer,
.alphabet = if (alphabet) |a| a else b64Alphabet,
};
}
pub fn decode(self: Self) !void {
_ = self;
// todo
}
};