impl migration to pdfium for decompress

2026-05-22 09:31:11 +01:00
parent 2f1fe2c80c
commit ec67f7e431
2 changed files with 73 additions and 26 deletions
@@ -1,5 +1,6 @@
 package stirling.software.SPDF.controller.api.misc;

+import java.io.File;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.HashSet;
@@ -30,6 +31,7 @@ import stirling.software.common.util.GeneralUtils;
 import stirling.software.common.util.TempFile;
 import stirling.software.common.util.TempFileManager;
 import stirling.software.common.util.WebResponseUtils;
+import stirling.software.jpdfium.PdfDocument;

@MiscApi
@Slf4j
@@ -51,23 +53,41 @@ public class DecompressPdfController {

        MultipartFile file = request.getFileInput();

-        try (PDDocument document = pdfDocumentFactory.load(file)) {
-            // Process all objects in document
-            processAllObjects(document);
-
-            // Save with explicit no compression to a temp file
-            TempFile tempOut = tempFileManager.createManagedTempFile(".pdf");
-            try {
-                document.save(tempOut.getFile(), CompressParameters.NO_COMPRESSION);
-            } catch (IOException e) {
-                tempOut.close();
-                throw e;
+        // JPDFium fast pre-validate: catches corrupt PDFs cheaply before the expensive PDFBox walk.
+        // JPDFium's FPDF_SaveAsCopy has no "uncompress streams" flag, so PDFBox does the actual
+        // work.
+        File inputTemp = null;
+        try {
+            inputTemp = tempFileManager.convertMultipartFileToFile(file);
+            try (PdfDocument ignored = PdfDocument.open(inputTemp.toPath())) {
+                // pre-validate only
+            } catch (Exception e) {
+                log.debug(
+                        "JPDFium pre-validate failed; proceeding with PDFBox: {}", e.getMessage());
            }

-            // Return the PDF as a streaming response
-            return WebResponseUtils.pdfFileToWebResponse(
-                    tempOut,
-                    GeneralUtils.generateFilename(file.getOriginalFilename(), "_decompressed.pdf"));
+            try (PDDocument document = pdfDocumentFactory.load(file)) {
+                // Walk every object and strip stream filters so PDFBox writes raw bytes
+                processAllObjects(document);
+
+                // Hybrid fallback: PDFium cannot save uncompressed, so use PDFBox NO_COMPRESSION
+                TempFile tempOut = tempFileManager.createManagedTempFile(".pdf");
+                try {
+                    document.save(tempOut.getFile(), CompressParameters.NO_COMPRESSION);
+                } catch (IOException e) {
+                    tempOut.close();
+                    throw e;
+                }
+
+                return WebResponseUtils.pdfFileToWebResponse(
+                        tempOut,
+                        GeneralUtils.generateFilename(
+                                file.getOriginalFilename(), "_decompressed.pdf"));
+            }
+        } finally {
+            if (inputTemp != null) {
+                tempFileManager.deleteTempFile(inputTemp);
+            }
        }
    }

@@ -75,7 +95,6 @@ public class DecompressPdfController {
        Set<COSBase> processed = new HashSet<>();
        COSDocument cosDoc = document.getDocument();

-        // Process all objects in the document
        for (COSObjectKey key : cosDoc.getXrefTable().keySet()) {
            COSObject obj = cosDoc.getObjectFromPool(key);
            processObject(obj, processed);
@@ -83,7 +102,6 @@ public class DecompressPdfController {
    }

    private void processObject(COSBase obj, Set<COSBase> processed) {
-        // Skip null objects or already processed objects to avoid infinite recursion
        if (obj == null || processed.contains(obj)) return;
        processed.add(obj);

@@ -97,19 +115,16 @@ public class DecompressPdfController {
    }

    private void processDictionary(COSDictionary dict, Set<COSBase> processed) {
-        // Process all dictionary entries
        for (COSName key : dict.keySet()) {
            processObject(dict.getDictionaryObject(key), processed);
        }

-        // If this is a stream, decompress it
        if (dict instanceof COSStream stream) {
            decompressStream(stream);
        }
    }

    private void processArray(COSArray array, Set<COSBase> processed) {
-        // Process all array elements
        for (int i = 0; i < array.size(); i++) {
            processObject(array.get(i), processed);
        }
@@ -119,33 +134,27 @@ public class DecompressPdfController {
        try {
            log.debug("Processing stream: {}", stream);

-            // Only remove filter information if it exists
            if (stream.containsKey(COSName.FILTER)
                    || stream.containsKey(COSName.DECODE_PARMS)
                    || stream.containsKey(COSName.D)) {

-                // Read the decompressed content first
                byte[] decompressedBytes;
                try (COSInputStream is = stream.createInputStream()) {
                    decompressedBytes = IOUtils.toByteArray(is);
                }

-                // Now remove filter information
                stream.removeItem(COSName.FILTER);
                stream.removeItem(COSName.DECODE_PARMS);
                stream.removeItem(COSName.D);

-                // Write the raw content back
                try (OutputStream out = stream.createRawOutputStream()) {
                    out.write(decompressedBytes);
                }

-                // Set the Length to reflect the new stream size
                stream.setInt(COSName.LENGTH, decompressedBytes.length);
            }
        } catch (IOException e) {
            ExceptionUtils.logException("stream decompression", e);
-            // Continue processing other streams even if this one fails
        }
    }
 }
@@ -1,6 +1,7 @@
 package stirling.software.SPDF.controller.api.misc;

 import static org.assertj.core.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.*;

@@ -68,6 +69,16 @@ class DecompressPdfControllerTest {
                            lenient().when(tf.getPath()).thenReturn(f.toPath());
                            return tf;
                        });
+        // Stub multipart-to-file conversion for the JPDFium pre-validate step
+        lenient()
+                .when(tempFileManager.convertMultipartFileToFile(any()))
+                .thenAnswer(
+                        inv -> {
+                            org.springframework.web.multipart.MultipartFile mf = inv.getArgument(0);
+                            File f = Files.createTempFile("input", ".pdf").toFile();
+                            java.nio.file.Files.write(f.toPath(), mf.getBytes());
+                            return f;
+                        });
    }

    private MockMultipartFile createRealPdf(String content) throws IOException {
@@ -209,6 +220,33 @@ class DecompressPdfControllerTest {
        assertThat(drainBody(response).length).isGreaterThan(0);
    }

+    @Test
+    void decompressPdf_oracleNoFilterEntries() throws IOException {
+        // PDFBox oracle: load the decompressed output and verify every COSStream has no /Filter
+        MockMultipartFile file = createRealPdf("Oracle decompression check");
+        PDFFile request = new PDFFile();
+        request.setFileInput(file);
+
+        PDDocument doc = Loader.loadPDF(file.getBytes());
+        when(pdfDocumentFactory.load(file)).thenReturn(doc);
+
+        ResponseEntity<Resource> response = controller.decompressPdf(request);
+        byte[] body = drainBody(response);
+
+        try (PDDocument result = Loader.loadPDF(body)) {
+            org.apache.pdfbox.cos.COSDocument cosDoc = result.getDocument();
+            for (org.apache.pdfbox.cos.COSObjectKey key : cosDoc.getXrefTable().keySet()) {
+                org.apache.pdfbox.cos.COSObject obj = cosDoc.getObjectFromPool(key);
+                org.apache.pdfbox.cos.COSBase base = obj.getObject();
+                if (base instanceof org.apache.pdfbox.cos.COSStream stream) {
+                    assertThat(stream.containsKey(org.apache.pdfbox.cos.COSName.FILTER))
+                            .as("stream %s should have no /Filter", key)
+                            .isFalse();
+                }
+            }
+        }
+    }
+
    @Test
    void decompressPdf_returnsOkContentType() throws IOException {
        MockMultipartFile file = createRealPdf("test");