Memory enhancements and PDF decompress API (#3129)

# Description of Changes

- PDF split by size to check size of PDF as it splits, avoids issue were
a PDFs size is different viewed vs saved due to compression caused by
repeated data etc.
- Additionally memory enhancements for PDF load to dynamically load in
memory vs scratch
- PDF Decompress API for PDF testing


## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/DeveloperGuide.md#6-testing)
for more details.

src/main/java/stirling/software/SPDF/controller/api/security/CertSignController.java

@@ -130,8 +130,8 @@ public class CertSignController {
             summary = "Sign PDF with a Digital Certificate",
             description =
                     "This endpoint accepts a PDF file, a digital certificate and related"
-                        + " information to sign the PDF. It then returns the digitally signed PDF"
-                        + " file. Input:PDF Output:PDF Type:SISO")
+                            + " information to sign the PDF. It then returns the digitally signed PDF"
+                            + " file. Input:PDF Output:PDF Type:SISO")
     public ResponseEntity<byte[]> signPDFWithCert(@ModelAttribute SignPDFWithCertRequest request)
             throws Exception {
         MultipartFile pdf = request.getFileInput();

src/main/java/stirling/software/SPDF/controller/api/security/GetInfoOnPDF.java

@@ -6,7 +6,6 @@ import java.nio.charset.StandardCharsets;
 import java.text.SimpleDateFormat;
 import java.util.*;
 
-import org.apache.pdfbox.Loader;
 import org.apache.pdfbox.cos.COSInputStream;
 import org.apache.pdfbox.cos.COSName;
 import org.apache.pdfbox.cos.COSString;
@@ -44,6 +43,7 @@ import org.apache.xmpbox.XMPMetadata;
 import org.apache.xmpbox.xml.DomXmpParser;
 import org.apache.xmpbox.xml.XmpParsingException;
 import org.apache.xmpbox.xml.XmpSerializer;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.ModelAttribute;
@@ -62,6 +62,7 @@ import io.swagger.v3.oas.annotations.tags.Tag;
 import lombok.extern.slf4j.Slf4j;
 
 import stirling.software.SPDF.model.api.PDFFile;
+import stirling.software.SPDF.service.CustomPDDocumentFactory;
 import stirling.software.SPDF.utils.WebResponseUtils;
 
 @RestController
@@ -72,6 +73,13 @@ public class GetInfoOnPDF {
 
     static ObjectMapper objectMapper = new ObjectMapper();
 
+    private final CustomPDDocumentFactory pdfDocumentFactory;
+
+    @Autowired
+    public GetInfoOnPDF(CustomPDDocumentFactory pdfDocumentFactory) {
+        this.pdfDocumentFactory = pdfDocumentFactory;
+    }
+
     private static void addOutlinesToArray(PDOutlineItem outline, ArrayNode arrayNode) {
         if (outline == null) return;
 
@@ -118,7 +126,7 @@ public class GetInfoOnPDF {
     @Operation(summary = "Summary here", description = "desc. Input:PDF Output:JSON Type:SISO")
     public ResponseEntity<byte[]> getPdfInfo(@ModelAttribute PDFFile request) throws IOException {
         MultipartFile inputFile = request.getFileInput();
-        try (PDDocument pdfBoxDoc = Loader.loadPDF(inputFile.getBytes()); ) {
+        try (PDDocument pdfBoxDoc = pdfDocumentFactory.load(inputFile.getBytes()); ) {
             ObjectMapper objectMapper = new ObjectMapper();
             ObjectNode jsonOutput = objectMapper.createObjectNode();
 

src/main/java/stirling/software/SPDF/controller/api/security/RedactController.java

@@ -3,8 +3,11 @@ package stirling.software.SPDF.controller.api.security;
 import java.awt.*;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 import org.apache.pdfbox.pdmodel.PDDocument;
 import org.apache.pdfbox.pdmodel.PDPage;
@@ -94,7 +97,10 @@ public class RedactController {
     private void redactAreas(
             List<RedactionArea> redactionAreas, PDDocument document, PDPageTree allPages)
             throws IOException {
-        Color redactColor = null;
+        // Group redaction areas by page
+        Map<Integer, List<RedactionArea>> redactionsByPage = new HashMap<>();
+
+        // Process and validate each redaction area
         for (RedactionArea redactionArea : redactionAreas) {
             if (redactionArea.getPage() == null
                     || redactionArea.getPage() <= 0
@@ -102,23 +108,44 @@ public class RedactController {
                     || redactionArea.getHeight() <= 0.0D
                     || redactionArea.getWidth() == null
                     || redactionArea.getWidth() <= 0.0D) continue;
-            PDPage page = allPages.get(redactionArea.getPage() - 1);
 
+            // Group by page number
+            redactionsByPage
+                    .computeIfAbsent(redactionArea.getPage(), k -> new ArrayList<>())
+                    .add(redactionArea);
+        }
+
+        // Process each page only once
+        for (Map.Entry<Integer, List<RedactionArea>> entry : redactionsByPage.entrySet()) {
+            Integer pageNumber = entry.getKey();
+            List<RedactionArea> areasForPage = entry.getValue();
+
+            if (pageNumber > allPages.getCount()) {
+                continue; // Skip if page number is out of bounds
+            }
+
+            PDPage page = allPages.get(pageNumber - 1);
+            PDRectangle box = page.getBBox();
+
+            // Create only one content stream per page
             PDPageContentStream contentStream =
                     new PDPageContentStream(
                             document, page, PDPageContentStream.AppendMode.APPEND, true, true);
-            redactColor = decodeOrDefault(redactionArea.getColor(), Color.BLACK);
-            contentStream.setNonStrokingColor(redactColor);
 
-            float x = redactionArea.getX().floatValue();
-            float y = redactionArea.getY().floatValue();
-            float width = redactionArea.getWidth().floatValue();
-            float height = redactionArea.getHeight().floatValue();
+            // Process all redactions for this page
+            for (RedactionArea redactionArea : areasForPage) {
+                Color redactColor = decodeOrDefault(redactionArea.getColor(), Color.BLACK);
+                contentStream.setNonStrokingColor(redactColor);
 
-            PDRectangle box = page.getBBox();
+                float x = redactionArea.getX().floatValue();
+                float y = redactionArea.getY().floatValue();
+                float width = redactionArea.getWidth().floatValue();
+                float height = redactionArea.getHeight().floatValue();
+
+                contentStream.addRect(x, box.getHeight() - y - height, width, height);
+                contentStream.fill();
+            }
 
-            contentStream.addRect(x, box.getHeight() - y - height, width, height);
-            contentStream.fill();
             contentStream.close();
         }
     }

src/main/java/stirling/software/SPDF/controller/api/security/SanitizeController.java

@@ -45,7 +45,7 @@ public class SanitizeController {
             summary = "Sanitize a PDF file",
             description =
                     "This endpoint processes a PDF file and removes specific elements based on the"
-                        + " provided options. Input:PDF Output:PDF Type:SISO")
+                            + " provided options. Input:PDF Output:PDF Type:SISO")
     public ResponseEntity<byte[]> sanitizePDF(@ModelAttribute SanitizePdfRequest request)
             throws IOException {
         MultipartFile inputFile = request.getFileInput();