Support linearized loading

fpdfsdk/src/fpdf_dataavail.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "../../public/fpdf_dataavail.h"
 #include "../include/fsdk_define.h"
 
 class CFPDF_FileAvailWrap : public IFX_FileAvail {
@@ skipping 68 matching lines @@
   pAvail->m_FileRead.Set(file);
   pAvail->m_pDataAvail =
       IPDF_DataAvail::Create(&pAvail->m_FileAvail, &pAvail->m_FileRead);
   return pAvail;
 }
 
 DLLEXPORT void STDCALL FPDFAvail_Destroy(FPDF_AVAIL avail) {
   delete (CFPDF_DataAvail*)avail;
 }
 
-DLLEXPORT int STDCALL FPDFAvail_IsDocAvail(FPDF_AVAIL avail,
-                                           FX_DOWNLOADHINTS* hints) {
-  if (avail == NULL || hints == NULL)
-    return 0;
+DLLEXPORT FX_BOOL STDCALL
+FPDFAvail_IsDocAvail(FPDF_AVAIL avail, FX_DOWNLOADHINTS* hints) {
+  if (!avail || !hints)
+    return true;
   CFPDF_DownloadHintsWrap hints_wrap(hints);
   return ((CFPDF_DataAvail*)avail)->m_pDataAvail->IsDocAvail(&hints_wrap);
 }
 
 DLLEXPORT FPDF_DOCUMENT STDCALL
 FPDFAvail_GetDocument(FPDF_AVAIL avail, FPDF_BYTESTRING password) {
   if (avail == NULL)
     return NULL;
   CPDF_Parser* pParser = new CPDF_Parser;
   pParser->SetPassword(password);
@@ skipping 10 matching lines @@
   return pParser->GetDocument();
 }
 
 DLLEXPORT int STDCALL FPDFAvail_GetFirstPageNum(FPDF_DOCUMENT doc) {
   if (doc == NULL)
     return 0;
   CPDF_Document* pDoc = (CPDF_Document*)doc;
   return ((CPDF_Parser*)pDoc->GetParser())->GetFirstPageNo();
 }
 
-DLLEXPORT int STDCALL FPDFAvail_IsPageAvail(FPDF_AVAIL avail,
-                                            int page_index,
-                                            FX_DOWNLOADHINTS* hints) {
-  if (avail == NULL || hints == NULL)
-    return 0;
+DLLEXPORT FX_BOOL STDCALL FPDFAvail_IsPageAvail(FPDF_AVAIL avail,
+                                                int page_index,
+                                                FX_DOWNLOADHINTS* hints) {
+  if (!avail || !hints)
+    return true;
   CFPDF_DownloadHintsWrap hints_wrap(hints);
   return ((CFPDF_DataAvail*)avail)
       ->m_pDataAvail->IsPageAvail(page_index, &hints_wrap);
 }
 
 DLLEXPORT int STDCALL FPDFAvail_IsFormAvail(FPDF_AVAIL avail,
                                             FX_DOWNLOADHINTS* hints) {
-  if (avail == NULL || hints == NULL)
-    return -1;
+  if (!avail || !hints)
+    return PDFFORM_AVAIL;
   CFPDF_DownloadHintsWrap hints_wrap(hints);
   return ((CFPDF_DataAvail*)avail)->m_pDataAvail->IsFormAvail(&hints_wrap);
 }
 
-DLLEXPORT FPDF_BOOL STDCALL FPDFAvail_IsLinearized(FPDF_AVAIL avail) {
-  if (avail == NULL)
-    return -1;
+DLLEXPORT int STDCALL FPDFAvail_IsLinearized(FPDF_AVAIL avail) {
+  if (!avail)
+    return PDF_FILE_UNKNOW;
   return ((CFPDF_DataAvail*)avail)->m_pDataAvail->IsLinearizedPDF();
 }