diff --git a/base64/build.zig b/base64/build.zig new file mode 100644 index 0000000..d193565 --- /dev/null +++ b/base64/build.zig @@ -0,0 +1,75 @@ +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(.{}); + + // We will also create a module for our other entry point, 'main.zig'. + const exe_mod = b.createModule(.{ + // `root_source_file` is the Zig "entry point" of the module. If a module + // only contains e.g. external object files, you can make this `null`. + // 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/main.zig"), + .target = target, + .optimize = optimize, + }); + + // This creates another `std.Build.Step.Compile`, but this one builds an executable + // rather than a static library. + const exe = b.addExecutable(.{ + .name = "base64", + .root_module = exe_mod, + }); + + // 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); + + const exe_unit_tests = b.addTest(.{ + .root_module = exe_mod, + }); + + 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_exe_unit_tests.step); +} diff --git a/base64/build.zig.zon b/base64/build.zig.zon new file mode 100644 index 0000000..1dd1852 --- /dev/null +++ b/base64/build.zig.zon @@ -0,0 +1,86 @@ +.{ + // This is the default name used by packages depending on this one. For + // example, when a user runs `zig fetch --save `, this field is used + // as the key in the `dependencies` table. Although the user can choose a + // different name, most users will stick with this provided value. + // + // It is redundant to include "zig" in this name because it is already + // within the Zig package namespace. + .name = .base64, + + // 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", + + // Together with name, this represents a globally unique package + // identifier. This field is generated by the Zig toolchain when the + // package is first created, and then *never changes*. This allows + // unambiguous detection of one package being an updated version of + // another. + // + // When forking a Zig project, this id should be regenerated (delete the + // field and run `zig build`) if the upstream project is still maintained. + // Otherwise, the fork is *hostile*, attempting to take control over the + // original project's identity. Thus it is recommended to leave the comment + // on the following line intact, so that it shows up in code reviews that + // modify the field. + .fingerprint = 0xcf92327682ca7f6d, // Changing this has security and trust implications. + + // Tracks the earliest Zig version that the package considers to be a + // supported use case. + .minimum_zig_version = "0.14.1", + + // 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 ` 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. If the contents of a URL change this will result in a hash mismatch + // // which will prevent zig from using it. + // .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. Only files listed here will remain on disk + // when using the zig package manager. As a rule of thumb, one should list + // files required for compilation plus any license(s). + // 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 = .{ + "build.zig", + "build.zig.zon", + "src", + // For example... + //"LICENSE", + //"README.md", + }, +} diff --git a/base64/src/base64.zig b/base64/src/base64.zig new file mode 100644 index 0000000..d0c1d31 --- /dev/null +++ b/base64/src/base64.zig @@ -0,0 +1,138 @@ +const std = @import("std"); + +pub const Base64 = struct { + _table: *const [64]u8, + + pub fn init() Base64 { + const upper = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; + const lower = "abcdefghijklmnopqrstuvwxyz"; + const numsym = "0123456789+/"; + + return Base64 { + ._table = upper ++ lower ++ numsym, + }; + } + + pub fn encode(self: Base64, allocator: std.mem.Allocator, input: [] const u8) ![]u8 { + if (input.len == 0) { + return ""; + } + + const n_out = try _calc_encode_length(input); + const out = try allocator.alloc(u8, n_out); + var buf = [3]u8{0, 0, 0}; + var count: u8 = 0; + var iout: u64 = 0; + + for (input, 0..) |_, i| { + buf[count] = input[i]; + count += 1; + if (count == 3) { + out[iout] = self._char_at(buf[0] >> 2); + out[iout + 1] = self._char_at(((buf[0] & 0x03) << 4) + (buf[1] >> 4)); + out[iout + 2] = self._char_at(((buf[1] & 0x0f) << 2) + (buf[2] >> 6)); + out[iout + 3] = self._char_at(buf[2] & 0x3f); + + iout += 4; + count = 0; + } + } + + if (count == 1) { + out[iout] = self._char_at(buf[0] >> 2); + out[iout + 1] = self._char_at((buf[0] & 0x03) << 4); + out[iout + 2] = '='; + out[iout + 3] = '='; + } + + if (count == 2) { + out[iout] = self._char_at(buf[0] >> 2); + out[iout + 1] = self._char_at(((buf[0] & 0x03) << 4) + (buf[1] >> 4)); + out[iout + 2] = self._char_at((buf[1] & 0x0f) << 2); + out[iout + 3] = '='; + + iout += 4; + } + + return out; + } + + pub fn decode(self: Base64, allocator: std.mem.Allocator, input: [] const u8) ![]u8 { + if (input.len == 0) { + return ""; + } + + const n_out = try _calc_decode_length(input); + const out = try allocator.alloc(u8, n_out); + var buf = [4]u8{0, 0, 0, 0}; + var count: u8 = 0; + var iout: u64 = 0; + + for (input, 0..) |_, i| { + buf[count] = self._char_index(input[i]); + count += 1; + if (count == 4) { + out[iout] = (buf[0] << 2) + (buf[1] >> 4); + if (buf[2] != 64) { + out[iout + 1] = (buf[1] << 4) + (buf[2] >> 2); + } + if (buf[3] != 64) { + out[iout + 2] = (buf[2] << 6) + buf[3]; + } + + iout += 3; + count = 0; + } + } + + return out; + } + + fn _char_at(self: Base64, index: usize) u8 { + return self._table[index]; + } + + fn _char_index(self: Base64, char: u8) u8 { + if (char == '=') { + return 64; + } + + var index: u8 = 0; + for (0..63) |i| { + if (self._char_at(i) == char) { + break; + } + index += 1; + } + + return index; + } + + fn _calc_encode_length(input: [] const u8) !usize { + if (input.len < 3) { + return 4; + } + + const n_groups = try std.math.divCeil(usize, input.len, 3); + + return n_groups * 4; + } + + fn _calc_decode_length(input: [] const u8) !usize { + if (input.len < 4) { + return 3; + } + + const n_groups = try std.math.divFloor(usize, input.len, 4); + + var groups: usize = n_groups * 3; + var i: usize = input.len - 1; + while (i > 0) : (i -= 1) { + if (input[i] == '=') { + groups -= 1; + } + } + + return groups; + } +}; diff --git a/base64/src/main.zig b/base64/src/main.zig new file mode 100644 index 0000000..5eaa933 --- /dev/null +++ b/base64/src/main.zig @@ -0,0 +1,19 @@ +const std = @import("std"); +const Base64 = @import("base64.zig").Base64; + +pub fn main() !void { + const stdout = std.io.getStdOut().writer(); + var memory_buffer: [1000]u8 = undefined; + var fba = std.heap.FixedBufferAllocator.init( + &memory_buffer + ); + const allocator = fba.allocator(); + + const text = "Testing some more stuff"; + const etext = "VGVzdGluZyBzb21lIG1vcmUgc3R1ZmY="; + const base64 = Base64.init(); + const encoded_text = try base64.encode(allocator, text); + const decoded_text = try base64.decode(allocator, etext); + try stdout.print("Encoded text: {s}\n", .{encoded_text}); + try stdout.print("Decoded text: {s}\n", .{decoded_text}); +}