add QPDF::processMemoryFile and API additions to support it

git-svn-id: svn+q:///qpdf/trunk@1034 71b93d88-0707-0410-a8cf-f5a4172ac649

ChangeLog

@@ -1,3 +1,8 @@
+2010-10-01  Jay Berkenbilt  <ejb@ql.org>
+
+	* include/qpdf/QPDF.hh: Add processMemoryFile method for
+	processing a PDF file from a memory buffer instead of a file.
+
 2010-09-24  Jay Berkenbilt  <ejb@ql.org>
 
 	* libqpdf/QPDF.cc: change private "file" method to be a

TODO

@@ -1,41 +1,3 @@
-2.2.1
-=====
-
-Add interface for working with in-memory PDF files.  Here's some code
-to work with.
-
-    Pl_Buffer b("b");
-    FILE* f = QUtil::fopen_wrapper(std::string("open ") + filename,
-				   fopen(filename, "rb"));
-    unsigned char buf[1024];
-    size_t bytes_read = 0;
-    while (true)
-    {
-	size_t len = fread(buf, 1, sizeof(buf), f);
-	if (len == 0)
-	{
-	    if (ferror(f))
-	    {
-		throw QPDFExc(qpdf_e_system,
-			      filename, "",
-			      0,
-			      "read");
-	    }
-	    else
-	    {
-		b.finish();
-		break;
-	    }
-	}
-	else
-	{
-	    b.write(buf, len);
-	    bytes_read += len;
-	}
-    }
-    fclose(f);
-    this->file = new BufferInputSource(filename, b.getBuffer());
-
 General
 =======
 

include/qpdf/Buffer.hh

@@ -15,8 +15,17 @@ class Buffer
   public:
     QPDF_DLL
     Buffer();
+
+    // Create a Buffer object whose memory is owned by the class and
+    // will be freed when the Buffer object is destroyed.
     QPDF_DLL
     Buffer(unsigned long size);
+
+    // Create a Buffer object whose memory is owned by the caller and
+    // will not be freed when the Buffer is destroyed.
+    QPDF_DLL
+    Buffer(unsigned char* buf, unsigned long size);
+
     QPDF_DLL
     Buffer(Buffer const&);
     QPDF_DLL
@@ -31,10 +40,11 @@ class Buffer
     unsigned char* getBuffer();
 
   private:
-    void init(unsigned long size);
+    void init(unsigned long size, unsigned char* buf, bool own_memory);
     void copy(Buffer const&);
     void destroy();
 
+    bool own_memory;
     unsigned long size;
     unsigned char* buf;
 };

include/qpdf/QPDF.hh

@@ -50,6 +50,15 @@ class QPDF
     QPDF_DLL
     void processFile(char const* filename, char const* password = 0);
 
+    // Parse a PDF file loaded into a memory buffer.  This works
+    // exactly like processFile except that the PDF file is in memory
+    // instead of on disk.  The description appears in any warning or
+    // error message in place of the file name.
+    QPDF_DLL
+    void processMemoryFile(char const* description,
+			   char const* buf, size_t length,
+			   char const* password = 0);
+
     // Parameter settings
 
     // If true, ignore any cross-reference streams in a hybrid file
@@ -362,7 +371,8 @@ class QPDF
     class BufferInputSource: public InputSource
     {
       public:
-	BufferInputSource(std::string const& description, Buffer* buf);
+	BufferInputSource(std::string const& description, Buffer* buf,
+			  bool own_memory = false);
 	virtual ~BufferInputSource();
 	virtual std::string const& getName() const;
 	virtual off_t tell();
@@ -372,6 +382,7 @@ class QPDF
 	virtual void unreadCh(char ch);
 
       private:
+	bool own_memory;
 	std::string description;
 	Buffer* buf;
 	off_t cur_offset;
@@ -410,7 +421,7 @@ class QPDF
 	off_t end_after_space;
     };
 
-    void parse();
+    void parse(char const* password);
     void warn(QPDFExc const& e);
     void setTrailer(QPDFObjectHandle obj);
     void read_xref(off_t offset);

libqpdf/Buffer.cc

@@ -4,17 +4,22 @@
 
 Buffer::Buffer()
 {
-    init(0);
+    init(0, 0, true);
 }
 
 Buffer::Buffer(unsigned long size)
 {
-    init(size);
+    init(size, 0, true);
+}
+
+Buffer::Buffer(unsigned char* buf, unsigned long size)
+{
+    init(size, buf, false);
 }
 
 Buffer::Buffer(Buffer const& rhs)
 {
-    init(0);
+    init(0, 0, true);
     copy(rhs);
 }
 
@@ -31,10 +36,18 @@ Buffer::~Buffer()
 }
 
 void
-Buffer::init(unsigned long size)
+Buffer::init(unsigned long size, unsigned char* buf, bool own_memory)
 {
+    this->own_memory = own_memory;
     this->size = size;
-    this->buf = (size ? new unsigned char[size] : 0);
+    if (own_memory)
+    {
+	this->buf = (size ? new unsigned char[size] : 0);
+    }
+    else
+    {
+	this->buf = buf;
+    }
 }
 
 void
@@ -43,7 +56,7 @@ Buffer::copy(Buffer const& rhs)
     if (this != &rhs)
     {
 	this->destroy();
-	this->init(rhs.size);
+	this->init(rhs.size, 0, true);
 	if (this->size)
 	{
 	    memcpy(this->buf, rhs.buf, this->size);
@@ -54,7 +67,10 @@ Buffer::copy(Buffer const& rhs)
 void
 Buffer::destroy()
 {
-    delete [] this->buf;
+    if (this->own_memory)
+    {
+	delete [] this->buf;
+    }
     this->size = 0;
     this->buf = 0;
 }

libqpdf/QPDF.cc

@@ -159,7 +159,8 @@ QPDF::FileInputSource::unreadCh(char ch)
 }
 
 QPDF::BufferInputSource::BufferInputSource(std::string const& description,
-					   Buffer* buf) :
+					   Buffer* buf, bool own_memory) :
+    own_memory(own_memory),
     description(description),
     buf(buf),
     cur_offset(0)
@@ -168,6 +169,10 @@ QPDF::BufferInputSource::BufferInputSource(std::string const& description,
 
 QPDF::BufferInputSource::~BufferInputSource()
 {
+    if (own_memory)
+    {
+	delete this->buf;
+    }
 }
 
 std::string const&
@@ -192,7 +197,7 @@ QPDF::BufferInputSource::seek(off_t offset, int whence)
 	break;
 
       case SEEK_END:
-	this->cur_offset = this->buf->getSize() - offset;
+	this->cur_offset = this->buf->getSize() + offset;
 	break;
 
       case SEEK_CUR:
@@ -306,11 +311,19 @@ QPDF::processFile(char const* filename, char const* password)
     FileInputSource* fi = new FileInputSource();
     this->file = fi;
     fi->setFilename(filename);
-    if (password)
-    {
-	this->provided_password = password;
-    }
-    parse();
+    parse(password);
+}
+
+void
+QPDF::processMemoryFile(char const* description,
+			char const* buf, size_t length,
+			char const* password)
+{
+    this->file =
+	new BufferInputSource(description,
+			      new Buffer((unsigned char*)buf, length),
+			      true);
+    parse(password);
 }
 
 void
@@ -340,11 +353,16 @@ QPDF::getWarnings()
 }
 
 void
-QPDF::parse()
+QPDF::parse(char const* password)
 {
     static PCRE header_re("^%PDF-(1.\\d+)\\b");
     static PCRE eof_re("(?s:startxref\\s+(\\d+)\\s+%%EOF\\b)");
 
+    if (password)
+    {
+	this->provided_password = password;
+    }
+
     std::string line = this->file->readLine();
     PCRE::Match m1 = header_re.match(line.c_str());
     if (m1)

qpdf/test_driver.cc

@@ -58,11 +58,53 @@ class Provider: public QPDFObjectHandle::StreamDataProvider
 void runtest(int n, char const* filename)
 {
     QPDF pdf;
+    PointerHolder<char> file_buf;
     if (n == 0)
     {
 	pdf.setAttemptRecovery(false);
     }
-    pdf.processFile(filename);
+    if (n % 2 == 0)
+    {
+	pdf.processFile(filename);
+    }
+    else
+    {
+	// Exercise processMemoryFile
+	FILE* f = QUtil::fopen_wrapper(std::string("open ") + filename,
+				       fopen(filename, "rb"));
+	fseek(f, 0, SEEK_END);
+	size_t size = (size_t) ftell(f);
+	fseek(f, 0, SEEK_SET);
+	file_buf = new char[size];
+	char* buf_p = file_buf.getPointer();
+	size_t bytes_read = 0;
+	size_t len = 0;
+	while ((len = fread(buf_p + bytes_read, 1, size - bytes_read, f)) > 0)
+	{
+	    bytes_read += len;
+	}
+	if (bytes_read != size)
+	{
+	    if (ferror(f))
+	    {
+		throw std::runtime_error(
+		    std::string("failure reading file ") + filename +
+		    " into memory: read " +
+		    QUtil::int_to_string(bytes_read) + "; wanted " +
+		    QUtil::int_to_string(size));
+	    }
+	    else
+	    {
+		throw std::logic_error(
+		    std::string("premature eof reading file ") + filename +
+		    " into memory: read " +
+		    QUtil::int_to_string(bytes_read) + "; wanted " +
+		    QUtil::int_to_string(size));
+	    }
+	}
+	fclose(f);
+	pdf.processMemoryFile(filename, buf_p, size);
+    }
 
     if ((n == 0) || (n == 1))
     {