Merge pull request #26 from gms1/package-sqlite-zip

package sqlite as zip and extract at build time

Author: gms1

deps/extract.js

@@ -0,0 +1,130 @@
+#!/usr/bin/env node
+'use strict';
+
+const fs = require('fs');
+const path = require('path');
+const zlib = require('zlib');
+
+const LOCAL_FILE_HEADER_SIG = 0x04034b50;
+const COMPRESSION_STORE = 0;
+const COMPRESSION_DEFLATE = 8;
+
+function extractZip(zipPath, destDir) {
+    const data = fs.readFileSync(zipPath);
+    let offset = 0;
+    let entries = 0;
+
+    // Detect top-level directory prefix to strip (e.g., "sqlite-amalgamation-3530100/")
+    let prefixToStrip = '';
+    let firstEntry = true;
+
+    while (offset < data.length) {
+        const sig = data.readUInt32LE(offset);
+        if (sig !== LOCAL_FILE_HEADER_SIG) {
+            break;
+        }
+
+        const compressionMethod = data.readUInt16LE(offset + 8);
+        const compressedSize = data.readUInt32LE(offset + 18);
+        const fileNameLength = data.readUInt16LE(offset + 26);
+        const extraFieldLength = data.readUInt16LE(offset + 28);
+
+        const fileName = data.toString('utf8', offset + 30, offset + 30 + fileNameLength);
+        const dataOffset = offset + 30 + fileNameLength + extraFieldLength;
+        const compressedData = data.subarray(dataOffset, dataOffset + compressedSize);
+
+        // Detect top-level directory prefix from first entry
+        if (firstEntry && fileName.includes('/')) {
+            prefixToStrip = fileName.substring(0, fileName.indexOf('/') + 1);
+            firstEntry = false;
+        }
+
+        // Strip prefix from filename
+        let outFileName = fileName;
+        if (prefixToStrip && outFileName.startsWith(prefixToStrip)) {
+            outFileName = outFileName.substring(prefixToStrip.length);
+        }
+
+        let fileData;
+        if (compressionMethod === COMPRESSION_STORE) {
+            fileData = compressedData;
+        } else if (compressionMethod === COMPRESSION_DEFLATE) {
+            fileData = zlib.inflateRawSync(compressedData);
+        } else {
+            throw new Error(`Unsupported compression method ${compressionMethod} for file ${fileName}`);
+        }
+
+        if (outFileName && !outFileName.endsWith('/')) {
+            const outPath = path.join(destDir, outFileName);
+          const resolvedDest = path.resolve(destDir);
+          const resolvedOut = path.resolve(outPath);
+          if (!resolvedOut.startsWith(resolvedDest + path.sep)) {
+            throw new Error(`Zip Slip detected: ${outFileName} resolves outside destination directory`);
+          }
+            const dir = path.dirname(outPath);
+            if (!fs.existsSync(dir)) {
+                fs.mkdirSync(dir, { recursive: true });
+            }
+            fs.writeFileSync(outPath, fileData);
+            entries++;
+        }
+
+        offset = dataOffset + compressedSize;
+    }
+
+    if (entries === 0) {
+        throw new Error('No files extracted — zip may be corrupted or empty');
+    }
+
+    return entries;
+}
+
+function main() {
+    const archivePath = path.resolve(process.argv[2]);
+    const destDir = path.resolve(process.argv[3]);
+
+    if (!archivePath || !destDir) {
+        console.error('Usage: extract.js <archive_path> <dest_dir>');
+        process.exit(1);
+    }
+
+    // Resolve archive path relative to script directory if not absolute
+    const zipFile = path.isAbsolute(archivePath)
+        ? archivePath
+        : path.join(__dirname, archivePath);
+
+    // Compute extraction directory: destDir + archive basename without .zip
+    const archiveName = path.basename(archivePath, '.zip');
+    const extractDir = path.join(destDir, archiveName);
+    const stampFile = path.join(extractDir, '.extract-stamp');
+
+    if (fs.existsSync(stampFile)) {
+        console.log(`[extract] Already extracted: ${extractDir}`);
+        process.exit(0);
+    }
+
+    if (!fs.existsSync(zipFile)) {
+        console.error(`[extract] ERROR: Zip file not found: ${zipFile}`);
+        process.exit(1);
+    }
+
+    if (fs.existsSync(extractDir)) {
+        console.log(`[extract] Removing stale extraction directory: ${extractDir}`);
+        fs.rmSync(extractDir, { recursive: true, force: true });
+    }
+
+    console.log(`[extract] Extracting ${path.basename(zipFile)}...`);
+    fs.mkdirSync(extractDir, { recursive: true });
+
+    try {
+        const entries = extractZip(zipFile, extractDir);
+        fs.writeFileSync(stampFile, `Extracted from ${path.basename(zipFile)}\n`);
+        console.log(`[extract] Extraction complete: ${entries} file(s) extracted to ${extractDir}`);
+    } catch (err) {
+        console.error(`[extract] ERROR: ${err.message}`);
+        fs.rmSync(extractDir, { recursive: true, force: true });
+        process.exit(1);
+    }
+}
+
+main();