[wip] rewrite

src/entry.ts

@@ -0,0 +1,125 @@
+// --- tar entry ---
+
+// prettier-ignore
+export type TarEntryHeaderKey =
+  "path" | "mode" | "uid" | "gid" | "size" | "mtime" | "checksum" | "typeFlag" |
+  "linkpath" | "magic" | "version" | "user" | "group" | "devMajor" | "devMinor" | "prefix" | "padding"
+
+// prettier-ignore
+export const tarEntryHeaderKeys: readonly TarEntryHeaderKey[] = Object.freeze([
+  "path", "mode", "uid", "gid", "size", "mtime", "checksum", "typeFlag", "linkpath",
+  "magic", "version", "user", "group", "devMajor", "devMinor", "prefix", "padding"
+]);
+
+// prettier-ignore
+export const tarNumericHeaders = new Set(["uid", "gid", "size", "mtime"] as const);
+export type TarNumericHeaderKey = "uid" | "gid" | "size" | "mtime";
+
+export const tarEntryHeaders: Record<
+  TarEntryHeaderKey,
+  [offset: number, size: number]
+> = Object.freeze({
+  path: [0, 100],
+  mode: [100, 8],
+  uid: [108, 8],
+  gid: [116, 8],
+  size: [124, 8],
+  mtime: [136, 12],
+  checksum: [148, 8],
+  typeFlag: [156, 1],
+  linkpath: [157, 100],
+  magic: [257, 6],
+  version: [263, 2],
+  user: [265, 32],
+  group: [297, 32],
+  devMajor: [329, 8],
+  devMinor: [337, 8],
+  prefix: [345, 155],
+  padding: [500, 12],
+});
+
+export type TarEntryHeaders = Record<
+  Exclude<TarEntryHeaderKey, TarNumericHeaderKey | "typeFlag">,
+  string
+> &
+  Record<TarNumericHeaderKey, number> & {
+    typeFlag: keyof typeof tarItemTypeMap | "";
+  };
+
+const u = undefined;
+// prettier-ignore
+export const emptyTarEntryHeaders: Record<TarEntryHeaderKey, undefined> = Object.freeze({
+  path: u, mode: u, uid: u, gid: u, size: u, mtime: u, checksum: u, typeFlag: u,linkpath: u,
+  magic: u, version: u, user: u, group: u, devMajor: u, devMinor: u, prefix: u, padding: u
+});
+
+export class TarEntryCtor {
+  data: Uint8Array;
+
+  path?: string = undefined;
+  mode?: string = undefined;
+  uid?: string = undefined;
+  gid?: string = undefined;
+  size?: string = undefined;
+  mtime?: string = undefined;
+  checksum?: string = undefined;
+  typeFlag?: string = undefined;
+  linkpath?: string = undefined;
+  magic?: string = undefined;
+  version?: string = undefined;
+  user?: string = undefined;
+  group?: string = undefined;
+  devMajor?: string = undefined;
+  devMinor?: string = undefined;
+  prefix?: string = undefined;
+  padding?: string = undefined;
+  constructor(data: Uint8Array) {
+    this.data = data;
+  }
+
+  [Symbol.for("nodejs.util.inspect.custom")]() {
+    return Object.fromEntries(
+      tarEntryHeaderKeys.map((key) => [key, this[key as keyof this]]),
+    );
+  }
+}
+
+// ---- type flags ---
+
+// prettier-ignore
+export type TarFileItemType = "file" | "hardLink" | "symbolicLink" | "characterDevice" | "blockDevice" | "directory" | "fifo" | "contiguousFile" | "globalExtendedHeader" | "extendedHeader" | "solarisAcl" | "gnuDirectory" | "gnuInodeMetadata" | "gnuLongLinkName" | "gnuLongFileName" | "gnuMultiVolume" | "gnuOldLongFileName" | "gnuSparseFile" | "solarisVolumeLabel" | "solarisOldExtendedHeader" | "gnuExtendedSparse";
+
+// prettier-ignore
+export type TarFileItemTypeValue = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "g" | "x" | "A" | "D" | "I" | "K" | "L" | "M" | "N" | "S" | "V" | "X" | "E";
+
+// prettier-ignore
+export const tarItemTypeMap = {
+  // Standard
+  "0": "file",                    // Regular file
+  "1": "hardLink",                // Hard link (meta)
+  "2": "symbolicLink",            // Symbolic link (meta)
+  "3": "characterDevice",         // Character device (meta)
+  "4": "blockDevice",             // Block device (meta)
+  "5": "directory",               // Directory (meta)
+  "6": "fifo",                    // Named pipe (FIFO) (meta)
+  "7": "contiguousFile",          // Contiguous file (rarely used, mostly for older systems)
+
+  // Extended headers
+  "g": "globalExtendedHeader",    // Global extended header (meta)
+  "x": "extendedHeader",          // Extended header for the next file (meta)
+
+  // GNU tar
+  "D": "gnuDirectory",             // GNU directory metadata (meta)
+  "I": "gnuInodeMetadata",         // GNU inode metadata
+  "K": "gnuLongLinkName",          // GNU long link name
+  "L": "gnuLongFileName",          // GNU long file name
+  "N": "gnuOldLongFileName",       // GNU long file name (old)
+  "M": "gnuMultiVolume",           // Multi-volume archive entry
+  "S": "gnuSparseFile",            // Sparse file (for files with holes)
+  "E": "gnuExtendedSparse",        // Extended sparse file (used in GNU tar for large sparse files)
+
+  // Solaris tar
+  "A": "solarisAcl",               // Solaris access control list
+  "V": "solarisVolumeLabel",       // Solaris volume label (meta)
+  "X": "solarisOldExtendedHeader", // Deprecated extended header format (meta)
+} as const satisfies Record<TarFileItemTypeValue, TarFileItemType>;