chore: cleaned up code

Author: aryanjassal

src/Generator.ts

@@ -1,5 +1,5 @@
 import type { FileType, FileStat } from './types';
-import { GeneratorState, EntryType } from './types';
+import { GeneratorState, EntryType, HeaderSize } from './types';
 import * as errors from './errors';
 import * as utils from './utils';
 import * as constants from './constants';
@@ -27,14 +27,14 @@ import * as constants from './constants';
  * 500      12      '\0' (unused)
  *
  * Note that all numbers are in stringified octal format.
- * 
+ *
  * The following data will be left blank (null):
  *  - Link name
  *  - Owner user name
  *  - Owner group name
  *  - Device major
  *  - Device minor
- *  
+ *
  *  This is because this implementation does not interact with linked files.
  *  Owner user name and group name cannot be extracted via regular stat-ing,
  *  so it is left blank. In virtual situations, this field won't be useful
@@ -43,16 +43,40 @@ import * as constants from './constants';
  *  these fields have been left blank.
  */
 class Generator {
-  protected state: GeneratorState = GeneratorState.READY;
+  protected state: GeneratorState = GeneratorState.HEADER;
   protected remainingBytes = 0;
 
-  protected generateHeader(filePath: string, type: FileType, stat: FileStat) {
+  protected generateHeader(filePath: string, type: FileType, stat: FileStat): Uint8Array {
     if (filePath.length > 255) {
       throw new errors.ErrorVirtualTarGeneratorInvalidFileName(
         'The file name must shorter than 255 characters',
       );
     }
 
+    if (stat?.size != null && stat?.size > 0o7777777) {
+      throw new errors.ErrorVirtualTarGeneratorInvalidStat(
+        'The file size must be smaller than 7.99 GiB (8,589,934,591 bytes)',
+      );
+    }
+
+    if (
+      stat?.username != null &&
+      stat?.username.length > HeaderSize.OWNER_USERNAME
+    ) {
+      throw new errors.ErrorVirtualTarGeneratorInvalidStat(
+        `The username must not exceed ${HeaderSize.OWNER_USERNAME} bytes`,
+      );
+    }
+
+    if (
+      stat?.groupname != null &&
+      stat?.groupname.length > HeaderSize.OWNER_GROUPNAME
+    ) {
+      throw new errors.ErrorVirtualTarGeneratorInvalidStat(
+        `The groupname must not exceed ${HeaderSize.OWNER_GROUPNAME} bytes`,
+      );
+    }
+
     const header = new Uint8Array(constants.BLOCK_SIZE);
 
     // Every directory in tar must have a trailing slash
@@ -66,6 +90,8 @@ class Generator {
     utils.writeFileMode(header, stat.mode);
     utils.writeOwnerUid(header, stat.uid);
     utils.writeOwnerGid(header, stat.gid);
+    utils.writeOwnerUserName(header, stat.username);
+    utils.writeOwnerGroupName(header, stat.groupname);
     utils.writeFileSize(header, stat.size);
     utils.writeFileMtime(header, stat.mtime);
 
@@ -77,11 +103,11 @@ class Generator {
   }
 
   generateFile(filePath: string, stat: FileStat): Uint8Array {
-    if (this.state === GeneratorState.READY) {
+    if (this.state === GeneratorState.HEADER) {
       // Make sure the size is valid
       if (stat.size == null) {
         throw new errors.ErrorVirtualTarGeneratorInvalidStat(
-          'Files should have valid file sizes',
+          'Files must have valid file sizes',
         );
       }
 
@@ -97,59 +123,58 @@ class Generator {
       return generatedBlock;
     }
     throw new errors.ErrorVirtualTarGeneratorInvalidState(
-      `Expected state ${GeneratorState[GeneratorState.READY]} but got ${
+      `Expected state ${GeneratorState[GeneratorState.HEADER]} but got ${
         GeneratorState[this.state]
       }`,
     );
   }
 
-  generateDirectory(filePath: string, stat: FileStat): Uint8Array {
-    if (this.state === GeneratorState.READY) {
+  generateDirectory(filePath: string, stat?: FileStat): Uint8Array {
+    if (this.state === GeneratorState.HEADER) {
+      // The size is zero for directories. Override this value in the stat if
+      // set.
       const directoryStat: FileStat = {
+        ...stat,
         size: 0,
-        mode: stat.mode,
-        mtime: stat.mtime,
-        uid: stat.uid,
-        gid: stat.gid,
       };
       return this.generateHeader(filePath, 'directory', directoryStat);
     }
     throw new errors.ErrorVirtualTarGeneratorInvalidState(
-      `Expected state ${GeneratorState[GeneratorState.READY]} but got ${
+      `Expected state ${GeneratorState[GeneratorState.HEADER]} but got ${
         GeneratorState[this.state]
       }`,
     );
   }
 
   generateExtended(size: number): Uint8Array {
-    if (this.state === GeneratorState.READY) {
+    if (this.state === GeneratorState.HEADER) {
       this.state = GeneratorState.DATA;
       this.remainingBytes = size;
       return this.generateHeader('./PaxHeader', 'extended', { size });
     }
     throw new errors.ErrorVirtualTarGeneratorInvalidState(
-      `Expected state ${GeneratorState[GeneratorState.READY]} but got ${
+      `Expected state ${GeneratorState[GeneratorState.HEADER]} but got ${
         GeneratorState[this.state]
       }`,
     );
   }
 
   generateData(data: Uint8Array): Uint8Array {
-    if (data.byteLength > constants.BLOCK_SIZE) {
-      throw new errors.ErrorVirtualTarGeneratorBlockSize(
-        `Expected data to be ${constants.BLOCK_SIZE} bytes but received ${data.byteLength} bytes`,
-      );
-    }
-
     if (this.state === GeneratorState.DATA) {
+      if (data.byteLength > constants.BLOCK_SIZE) {
+        throw new errors.ErrorVirtualTarGeneratorBlockSize(
+          `Expected data to be ${constants.BLOCK_SIZE} bytes but received ${data.byteLength} bytes`,
+        );
+      }
+
       if (this.remainingBytes >= constants.BLOCK_SIZE) {
         this.remainingBytes -= constants.BLOCK_SIZE;
-        if (this.remainingBytes === 0) this.state = GeneratorState.READY;
+        if (this.remainingBytes === 0) this.state = GeneratorState.HEADER;
         return data;
       } else {
         // Update state
         this.remainingBytes = 0;
-        this.state = GeneratorState.READY;
+        this.state = GeneratorState.HEADER;
 
         // Pad the remaining data with nulls
         const paddedData = new Uint8Array(constants.BLOCK_SIZE);
@@ -168,9 +193,9 @@ class Generator {
   // Creates a single null block. A null block is a block filled with all zeros.
   // This is needed to end the archive, as two of these blocks mark the end of
   // archive.
-  generateEnd() {
+  generateEnd(): Uint8Array {
     switch (this.state) {
-      case GeneratorState.READY:
+      case GeneratorState.HEADER:
         this.state = GeneratorState.NULL;
         break;
       case GeneratorState.NULL: