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| 1 | +//! Compatibility layer for Zig 0.16-dev. |
| 2 | +//! |
| 3 | +//! Replaces removed APIs: |
| 4 | +//! - std.fs.cwd().openFile/createFile/deleteFile → raw POSIX fd ops |
| 5 | +//! - std.io.fixedBufferStream → MemStream (in-memory writer/reader) |
| 6 | +//! - std.time.nanoTimestamp() → clock_gettime(REALTIME) |
| 7 | +//! - std.Thread.sleep(ns) → linux.nanosleep |
| 8 | + |
| 9 | +const std = @import("std"); |
| 10 | +const posix = std.posix; |
| 11 | +const linux = std.os.linux; |
| 12 | +const Allocator = std.mem.Allocator; |
| 13 | + |
| 14 | +// Minimal stat struct matching Linux x86_64 struct stat (for fstat) |
| 15 | +const Stat = extern struct { |
| 16 | + dev: u64, |
| 17 | + ino: u64, |
| 18 | + nlink: u64, |
| 19 | + mode: u32, |
| 20 | + uid: u32, |
| 21 | + gid: u32, |
| 22 | + __pad0: u32 = 0, |
| 23 | + rdev: u64, |
| 24 | + size: i64, |
| 25 | + blksize: i64, |
| 26 | + blocks: i64, |
| 27 | + atim: linux.timespec, |
| 28 | + mtim: linux.timespec, |
| 29 | + ctim: linux.timespec, |
| 30 | + __unused: [3]i64 = .{ 0, 0, 0 }, |
| 31 | +}; |
| 32 | + |
| 33 | +// libc fstat — std.c.fstat is void on Linux in 0.16-dev |
| 34 | +extern "c" fn fstat(fd: posix.fd_t, buf: *Stat) c_int; |
| 35 | + |
| 36 | +// ── File operations (replaces removed std.fs.cwd()) ───────────── |
| 37 | + |
| 38 | +pub const File = struct { |
| 39 | + fd: posix.fd_t, |
| 40 | + |
| 41 | + pub fn close(self: File) void { |
| 42 | + _ = posix.system.close(self.fd); |
| 43 | + } |
| 44 | + |
| 45 | + /// Read entire file contents into an allocator-owned buffer (up to max_bytes). |
| 46 | + pub fn readToEndAlloc(self: File, allocator: Allocator, max_bytes: usize) ![]u8 { |
| 47 | + // Get file size via fstat |
| 48 | + var stat_buf: Stat = undefined; |
| 49 | + const stat_rc = fstat(self.fd, &stat_buf); |
| 50 | + if (stat_rc != 0) return error.StatFailed; |
| 51 | + const size: usize = @intCast(stat_buf.size); |
| 52 | + if (size > max_bytes) return error.FileTooBig; |
| 53 | + |
| 54 | + const buf = try allocator.alloc(u8, size); |
| 55 | + errdefer allocator.free(buf); |
| 56 | + |
| 57 | + var total: usize = 0; |
| 58 | + while (total < size) { |
| 59 | + const n = posix.read(self.fd, buf[total..]) catch |err| switch (err) { |
| 60 | + else => return error.ReadFailed, |
| 61 | + }; |
| 62 | + if (n == 0) break; |
| 63 | + total += n; |
| 64 | + } |
| 65 | + return buf[0..total]; |
| 66 | + } |
| 67 | + |
| 68 | + /// Read all bytes into a pre-allocated buffer. Returns number of bytes read. |
| 69 | + pub fn readAll(self: File, buf: []u8) !usize { |
| 70 | + var total: usize = 0; |
| 71 | + while (total < buf.len) { |
| 72 | + const n = posix.read(self.fd, buf[total..]) catch |err| switch (err) { |
| 73 | + else => return error.ReadFailed, |
| 74 | + }; |
| 75 | + if (n == 0) break; |
| 76 | + total += n; |
| 77 | + } |
| 78 | + return total; |
| 79 | + } |
| 80 | + |
| 81 | + pub fn writeAll(self: File, data: []const u8) !void { |
| 82 | + var total: usize = 0; |
| 83 | + while (total < data.len) { |
| 84 | + const rc = std.c.write(self.fd, data[total..].ptr, data.len - total); |
| 85 | + if (rc < 0) return error.WriteFailed; |
| 86 | + if (rc == 0) return error.WriteFailed; |
| 87 | + total += @intCast(rc); |
| 88 | + } |
| 89 | + } |
| 90 | + |
| 91 | + /// Get file size. |
| 92 | + pub fn stat(self: File) !struct { size: usize } { |
| 93 | + var stat_buf: Stat = undefined; |
| 94 | + const stat_rc = fstat(self.fd, &stat_buf); |
| 95 | + if (stat_rc != 0) return error.StatFailed; |
| 96 | + return .{ .size = @intCast(stat_buf.size) }; |
| 97 | + } |
| 98 | +}; |
| 99 | + |
| 100 | +/// Open a file relative to CWD. Replaces std.fs.cwd().openFile(). |
| 101 | +pub fn openFile(path: []const u8, comptime _: struct {}) !File { |
| 102 | + const fd = try posix.openat(posix.AT.FDCWD, path, .{ .ACCMODE = .RDONLY }, 0); |
| 103 | + return .{ .fd = fd }; |
| 104 | +} |
| 105 | + |
| 106 | +/// Create a file relative to CWD. Replaces std.fs.cwd().createFile(). |
| 107 | +pub fn createFile(path: []const u8, comptime _: struct {}) !File { |
| 108 | + const fd = try posix.openat(posix.AT.FDCWD, path, .{ |
| 109 | + .ACCMODE = .WRONLY, |
| 110 | + .CREAT = true, |
| 111 | + .TRUNC = true, |
| 112 | + }, 0o644); |
| 113 | + return .{ .fd = fd }; |
| 114 | +} |
| 115 | + |
| 116 | +/// Check if a file is accessible (exists and readable). |
| 117 | +pub fn access(path: []const u8) bool { |
| 118 | + const fd = posix.openat(posix.AT.FDCWD, path, .{ .ACCMODE = .RDONLY }, 0) catch return false; |
| 119 | + _ = posix.system.close(fd); |
| 120 | + return true; |
| 121 | +} |
| 122 | + |
| 123 | +/// Delete a file. Replaces std.fs.cwd().deleteFile(). |
| 124 | +pub fn deleteFile(path_z: [*:0]const u8) void { |
| 125 | + _ = std.c.unlink(path_z); |
| 126 | +} |
| 127 | + |
| 128 | +// ── In-memory stream (replaces removed std.io.fixedBufferStream) ── |
| 129 | + |
| 130 | +/// Minimal in-memory writer that provides writeAll/writeInt/writeByte. |
| 131 | +pub const MemWriter = struct { |
| 132 | + buffer: []u8, |
| 133 | + pos: usize = 0, |
| 134 | + |
| 135 | + pub fn writeAll(self: *MemWriter, data: []const u8) !void { |
| 136 | + if (self.pos + data.len > self.buffer.len) return error.NoSpaceLeft; |
| 137 | + @memcpy(self.buffer[self.pos..][0..data.len], data); |
| 138 | + self.pos += data.len; |
| 139 | + } |
| 140 | + |
| 141 | + pub fn writeByte(self: *MemWriter, byte: u8) !void { |
| 142 | + if (self.pos >= self.buffer.len) return error.NoSpaceLeft; |
| 143 | + self.buffer[self.pos] = byte; |
| 144 | + self.pos += 1; |
| 145 | + } |
| 146 | + |
| 147 | + pub fn writeInt(self: *MemWriter, comptime T: type, value: T, comptime endian: std.builtin.Endian) !void { |
| 148 | + const bytes = std.mem.toBytes(if (endian == .big) std.mem.nativeToBig(T, value) else std.mem.nativeToLittle(T, value)); |
| 149 | + try self.writeAll(&bytes); |
| 150 | + } |
| 151 | + |
| 152 | + pub fn getWritten(self: *const MemWriter) []const u8 { |
| 153 | + return self.buffer[0..self.pos]; |
| 154 | + } |
| 155 | +}; |
| 156 | + |
| 157 | +/// Minimal in-memory reader that provides readAll/readInt/readByte. |
| 158 | +pub const MemReader = struct { |
| 159 | + buffer: []const u8, |
| 160 | + pos: usize = 0, |
| 161 | + |
| 162 | + pub fn readAll(self: *MemReader, dest: []u8) !usize { |
| 163 | + const avail = self.buffer.len - self.pos; |
| 164 | + const n = @min(avail, dest.len); |
| 165 | + @memcpy(dest[0..n], self.buffer[self.pos..][0..n]); |
| 166 | + self.pos += n; |
| 167 | + return n; |
| 168 | + } |
| 169 | + |
| 170 | + pub fn readByte(self: *MemReader) !u8 { |
| 171 | + if (self.pos >= self.buffer.len) return error.EndOfStream; |
| 172 | + const byte = self.buffer[self.pos]; |
| 173 | + self.pos += 1; |
| 174 | + return byte; |
| 175 | + } |
| 176 | + |
| 177 | + pub fn readInt(self: *MemReader, comptime T: type, comptime endian: std.builtin.Endian) !T { |
| 178 | + const size = @sizeOf(T); |
| 179 | + if (self.pos + size > self.buffer.len) return error.EndOfStream; |
| 180 | + const bytes = self.buffer[self.pos..][0..size]; |
| 181 | + self.pos += size; |
| 182 | + const raw = std.mem.bytesToValue(T, bytes); |
| 183 | + return if (endian == .big) std.mem.bigToNative(T, raw) else std.mem.littleToNative(T, raw); |
| 184 | + } |
| 185 | +}; |
| 186 | + |
| 187 | +/// Minimal dynamic writer backed by an allocator (replaces ArrayListAligned + writer). |
| 188 | +pub const DynWriter = struct { |
| 189 | + items: []u8 = &.{}, |
| 190 | + len: usize = 0, |
| 191 | + allocator: Allocator, |
| 192 | + |
| 193 | + pub fn writeAll(self: *DynWriter, data: []const u8) !void { |
| 194 | + try self.ensureCapacity(self.len + data.len); |
| 195 | + @memcpy(self.items[self.len..][0..data.len], data); |
| 196 | + self.len += data.len; |
| 197 | + } |
| 198 | + |
| 199 | + pub fn writeByte(self: *DynWriter, byte: u8) !void { |
| 200 | + try self.ensureCapacity(self.len + 1); |
| 201 | + self.items[self.len] = byte; |
| 202 | + self.len += 1; |
| 203 | + } |
| 204 | + |
| 205 | + pub fn writeInt(self: *DynWriter, comptime T: type, value: T, comptime endian: std.builtin.Endian) !void { |
| 206 | + const bytes = std.mem.toBytes(if (endian == .big) std.mem.nativeToBig(T, value) else std.mem.nativeToLittle(T, value)); |
| 207 | + try self.writeAll(&bytes); |
| 208 | + } |
| 209 | + |
| 210 | + pub fn getWritten(self: *const DynWriter) []const u8 { |
| 211 | + return self.items[0..self.len]; |
| 212 | + } |
| 213 | + |
| 214 | + pub fn deinit(self: *DynWriter) void { |
| 215 | + if (self.items.len > 0) self.allocator.free(self.items); |
| 216 | + self.* = .{ .allocator = self.allocator }; |
| 217 | + } |
| 218 | + |
| 219 | + fn ensureCapacity(self: *DynWriter, needed: usize) !void { |
| 220 | + if (needed <= self.items.len) return; |
| 221 | + var new_cap = if (self.items.len == 0) @as(usize, 256) else self.items.len; |
| 222 | + while (new_cap < needed) new_cap *= 2; |
| 223 | + const new_buf = try self.allocator.alloc(u8, new_cap); |
| 224 | + if (self.len > 0) @memcpy(new_buf[0..self.len], self.items[0..self.len]); |
| 225 | + if (self.items.len > 0) self.allocator.free(self.items); |
| 226 | + self.items = new_buf; |
| 227 | + } |
| 228 | +}; |
| 229 | + |
| 230 | +// ── Time (replaces removed std.time.nanoTimestamp) ─────────────── |
| 231 | + |
| 232 | +pub fn nanoTimestamp() i128 { |
| 233 | + var ts: linux.timespec = undefined; |
| 234 | + _ = linux.clock_gettime(.REALTIME, &ts); |
| 235 | + return @as(i128, ts.sec) * std.time.ns_per_s + ts.nsec; |
| 236 | +} |
| 237 | + |
| 238 | +// ── Sleep (replaces removed std.Thread.sleep) ──────────────────── |
| 239 | + |
| 240 | +pub fn sleepNanos(ns: u64) void { |
| 241 | + const req = linux.timespec{ .sec = @intCast(ns / std.time.ns_per_s), .nsec = @intCast(ns % std.time.ns_per_s) }; |
| 242 | + _ = linux.nanosleep(&req, null); |
| 243 | +} |
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