Bug #8305 (Implement cache), r: valeski, rickg

The storage stream provides an internal buffer that
can be filled by a client using a single output
stream.  One or more independent input streams can
be created to read the data out non-destructively.
The implementation uses a segmented buffer
internally to avoid realloc'ing of large buffers.

xpcom/io/nsBinaryStream.cpp

@@ -0,0 +1,361 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * The contents of this file are subject to the Netscape Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/NPL/
+ *  
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *  
+ * The Original Code is Mozilla Communicator client code, released
+ * March 31, 1998.
+ * 
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation. Portions created by Netscape are
+ * Copyright (C) 1998-1999 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ */
+
+/**
+ * This file contains implementations of the nsIBinaryInputStream and
+ * nsIBinaryOutputStream interfaces.  Together, these interfaces allows reading
+ * and writing of primitive data types (integers, floating-point values,
+ * booleans, etc.) to a stream in a binary, untagged, fixed-endianness format.
+ * This might be used, for example, to implement network protocols or to
+ * produce architecture-neutral binary disk files, i.e. ones that can be read
+ * and written by both big-endian and little-endian platforms.  Output is
+ * written in big-endian order (high-order byte first), as this is traditional
+ * network order.
+ *
+ * @See nsIBinaryInputStream
+ * @See nsIBinaryOutputStream
+ */
+#include "nsBinaryStream.h"
+#include "nsIAllocator.h"
+
+// Swap macros, used to convert to/from canonical (big-endian) format
+#ifdef IS_LITTLE_ENDIAN
+#    define SWAP16(x) ((((x) & 0xff) << 8) | (((x) >> 8) & 0xff))
+#    define SWAP32(x) ((SWAP16((x) & 0xffff) << 16) | (SWAP16((x) >> 16)))
+#else
+#    ifndef IS_BIG_ENDIAN
+#        error "Unknown endianness"
+#    endif
+#    define SWAP16(x) (x)
+#    define SWAP32(x) (x)
+#endif
+
+nsBinaryOutputStream::nsBinaryOutputStream(nsIOutputStream* aStream): mOutputStream(aStream)
+{
+    NS_INIT_REFCNT();
+}
+
+NS_IMPL_ISUPPORTS(nsBinaryOutputStream, NS_GET_IID(nsIBinaryOutputStream))
+
+NS_IMETHODIMP
+nsBinaryOutputStream::Flush() { return mOutputStream->Flush(); }
+
+NS_IMETHODIMP
+nsBinaryOutputStream::Close() { return mOutputStream->Close(); }
+
+NS_IMETHODIMP
+nsBinaryOutputStream::Write(const char *aBuf, PRUint32 aCount, PRUint32 *aActualBytes)
+{
+    return mOutputStream->Write(aBuf, aCount, aActualBytes);
+}
+
+NS_IMETHODIMP
+nsBinaryOutputStream::SetOutputStream(nsIOutputStream *aOutputStream)
+{
+    NS_ENSURE_ARG_POINTER(aOutputStream);
+    mOutputStream = aOutputStream;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBinaryOutputStream::WriteBoolean(PRBool aBoolean)
+{
+    return Write8(aBoolean);
+}
+
+NS_IMETHODIMP
+nsBinaryOutputStream::Write8(PRUint8 aByte)
+{
+    nsresult rv;
+    PRUint32 bytesWritten;
+
+    rv = Write((const char*)&aByte, sizeof aByte, &bytesWritten);
+    if (bytesWritten != sizeof aByte)
+        return NS_ERROR_FAILURE;
+    return rv;
+}
+
+NS_IMETHODIMP
+nsBinaryOutputStream::Write16(PRUint16 a16)
+{
+    nsresult rv;
+    PRUint32 bytesWritten;
+
+    a16 = SWAP16(a16);
+    rv = Write((const char*)&a16, sizeof a16, &bytesWritten);
+    if (bytesWritten != sizeof a16)
+        return NS_ERROR_FAILURE;
+    return rv;
+}
+
+NS_IMETHODIMP
+nsBinaryOutputStream::Write32(PRUint32 a32)
+{
+    nsresult rv;
+    PRUint32 bytesWritten;
+
+    a32 = SWAP32(a32);
+    rv = Write((const char*)&a32, sizeof a32, &bytesWritten);
+    if (bytesWritten != sizeof a32)
+        return NS_ERROR_FAILURE;
+    return rv;
+}
+
+NS_IMETHODIMP
+nsBinaryOutputStream::Write64(PRUint64 a64)
+{
+    nsresult rv;
+    PRUint32* raw32 = (PRUint32*)&a64;
+
+#ifdef IS_BIG_ENDIAN
+    rv = Write32(raw32[0]);
+    if (NS_FAILED(rv)) return rv;
+    return Write32(raw32[1]);
+#else
+    rv = Write32(raw32[1]);
+    if (NS_FAILED(rv)) return rv;
+    return Write32(raw32[0]);
+#endif
+}
+
+NS_IMETHODIMP
+nsBinaryOutputStream::WriteFloat(float aFloat)
+{
+    NS_ASSERTION(sizeof(float) == sizeof (PRUint32),
+                 "False assumption about sizeof(float)");
+    return Write32(*NS_REINTERPRET_CAST(PRUint32*, &aFloat));
+}
+
+NS_IMETHODIMP
+nsBinaryOutputStream::WriteDouble(double aDouble)
+{
+    NS_ASSERTION(sizeof(double) == sizeof(PRUint64),
+                 "False assumption about sizeof(double)");
+    return Write64(*NS_REINTERPRET_CAST(PRUint64*,&aDouble));
+}
+
+NS_IMETHODIMP
+nsBinaryOutputStream::WriteStringZ(const char *aString)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsBinaryOutputStream::WriteWStringZ(const PRUnichar* aString)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsBinaryOutputStream::WriteUtf8Z(const PRUnichar* aString)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsBinaryOutputStream::WriteBytes(const char *aString, PRUint32 aLength)
+{
+    nsresult rv;
+    PRUint32 bytesWritten;
+
+    rv = Write(aString, aLength, &bytesWritten);
+    if (bytesWritten != aLength)
+        return NS_ERROR_FAILURE;
+    return rv;
+}
+
+NS_IMETHODIMP
+nsBinaryOutputStream::WriteString(nsString* aString)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+nsBinaryInputStream::nsBinaryInputStream(nsIInputStream* aStream): mInputStream(aStream) { NS_INIT_REFCNT(); }
+
+NS_IMPL_ISUPPORTS(nsBinaryInputStream, NS_GET_IID(nsIBinaryInputStream))
+
+NS_IMETHODIMP
+nsBinaryInputStream::Available(PRUint32* aResult) { return mInputStream->Available(aResult); }
+
+NS_IMETHODIMP
+nsBinaryInputStream::Read(char* aBuffer, PRUint32 aCount, PRUint32 *aNumRead)
+{
+    return mInputStream->Read(aBuffer, aCount, aNumRead);
+}
+
+NS_IMETHODIMP
+nsBinaryInputStream::Close() { return mInputStream->Close(); }
+
+NS_IMETHODIMP
+nsBinaryInputStream::SetInputStream(nsIInputStream *aInputStream)
+{
+    NS_ENSURE_ARG_POINTER(aInputStream);
+    mInputStream = aInputStream;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBinaryInputStream::ReadBoolean(PRBool* aBoolean)
+{
+    PRUint8 byteResult;
+    nsresult rv = Read8(&byteResult);
+    *aBoolean = byteResult;
+    return rv;
+}
+
+NS_IMETHODIMP
+nsBinaryInputStream::Read8(PRUint8* aByte)
+{
+    nsresult rv;
+    PRUint32 bytesRead;
+    
+    rv = Read((char*)aByte, sizeof(*aByte), &bytesRead);
+    if (bytesRead != sizeof (*aByte))
+        return NS_ERROR_FAILURE;
+    return rv;
+}
+
+NS_IMETHODIMP
+nsBinaryInputStream::Read16(PRUint16* a16)
+{
+    nsresult rv;
+    PRUint32 bytesRead;
+
+    rv = Read((char*)a16, sizeof *a16, &bytesRead);
+    if (bytesRead != sizeof *a16)
+        return NS_ERROR_FAILURE;
+    *a16 = SWAP16(*a16);
+    return rv;
+}
+
+NS_IMETHODIMP
+nsBinaryInputStream::Read32(PRUint32* a32)
+{
+    nsresult rv;
+    PRUint32 bytesRead;
+
+    rv = Read((char*)a32, sizeof *a32, &bytesRead);
+    if (bytesRead != sizeof *a32)
+        return NS_ERROR_FAILURE;
+    *a32 = SWAP32(*a32);
+    return rv;
+}
+
+NS_IMETHODIMP
+nsBinaryInputStream::Read64(PRUint64* a64)
+{
+    nsresult rv;
+    PRUint32* raw32 = (PRUint32*)a64;
+
+#ifdef IS_BIG_ENDIAN
+    rv = Read32(&raw32[0]);
+    if (NS_FAILED(rv)) return rv;
+    return Read32(&raw32[1]);
+#else
+    rv = Read32(&raw32[1]);
+    if (NS_FAILED(rv)) return rv;
+    return Read32(&raw32[0]);
+#endif
+}
+
+NS_IMETHODIMP
+nsBinaryInputStream::ReadFloat(float* aFloat)
+{
+    NS_ASSERTION(sizeof(float) == sizeof (PRUint32),
+		 "False assumption about sizeof(float)");
+    return Read32(NS_REINTERPRET_CAST(PRUint32*, aFloat));
+}
+
+NS_IMETHODIMP
+nsBinaryInputStream::ReadDouble(double* aDouble)
+{
+    NS_ASSERTION(sizeof(double) == sizeof(PRUint64),
+		 "False assumption about sizeof(double)");
+    return Read64(NS_REINTERPRET_CAST(PRUint64*, aDouble));
+}
+
+NS_IMETHODIMP
+nsBinaryInputStream::ReadStringZ(char* *aString)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsBinaryInputStream::ReadWStringZ(PRUnichar* *aString)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsBinaryInputStream::ReadUtf8Z(PRUnichar* *aString)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsBinaryInputStream::ReadBytes(char* *aString, PRUint32 aLength)
+{
+    nsresult rv;
+    PRUint32 bytesRead;
+    char* s;
+
+    s = (char*)nsAllocator::Alloc(aLength);
+    if (!s)
+        return NS_ERROR_OUT_OF_MEMORY;
+
+    rv = Read(s, aLength, &bytesRead);
+    if (NS_FAILED(rv)) return rv;
+    if (bytesRead != aLength)
+	return NS_ERROR_FAILURE;
+
+    *aString = s;
+    return NS_OK;
+}
+
+NS_IMETHODIMP
+nsBinaryInputStream::ReadString(nsString* *aString)
+{
+    return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_COM nsresult
+NS_NewBinaryOutputStream(nsIBinaryOutputStream* *aResult, nsIOutputStream* aDestStream)
+{
+    NS_ENSURE_ARG_POINTER(aResult);
+    nsIBinaryOutputStream *stream = new nsBinaryOutputStream(aDestStream);
+    if (!stream)
+        return NS_ERROR_OUT_OF_MEMORY;
+    NS_ADDREF(stream);
+    *aResult = stream;
+    return NS_OK;
+}
+
+NS_COM nsresult
+NS_NewBinaryInputStream(nsIBinaryInputStream* *aResult, nsIInputStream* aSrcStream)
+{
+    NS_ENSURE_ARG_POINTER(aResult);
+    nsIBinaryInputStream *stream = new nsBinaryInputStream(aSrcStream);
+    if (!stream)
+        return NS_ERROR_OUT_OF_MEMORY;
+    NS_ADDREF(stream);
+    *aResult = stream;
+    return NS_OK;
+}

xpcom/io/nsBinaryStream.h

@@ -0,0 +1,72 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * The contents of this file are subject to the Netscape Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/NPL/
+ *  
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *  
+ * The Original Code is Mozilla Communicator client code, released
+ * March 31, 1998.
+ * 
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation. Portions created by Netscape are
+ * Copyright (C) 1998-1999 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ */
+
+#include "nsIBinaryInputStream.h"
+#include "nsIBinaryOutputStream.h"
+#include "nsCOMPtr.h"
+
+class nsBinaryOutputStream : public nsIBinaryOutputStream
+{
+public:
+    nsBinaryOutputStream(nsIOutputStream *aStream);
+    ~nsBinaryOutputStream() {};
+
+private:
+    
+    // nsISupports methods
+    NS_DECL_ISUPPORTS
+
+    // nsIBaseStream methods
+    NS_DECL_NSIBASESTREAM
+
+    // nsIOutputStream methods
+    NS_DECL_NSIOUTPUTSTREAM
+
+    // nsIBinaryOutputStream methods
+    NS_DECL_NSIBINARYOUTPUTSTREAM
+    
+protected:
+    nsCOMPtr<nsIOutputStream> mOutputStream;
+};
+
+class nsBinaryInputStream : public nsIBinaryInputStream
+{
+public:
+    nsBinaryInputStream(nsIInputStream *aStream);
+    ~nsBinaryInputStream() {};
+
+private:
+    // nsISupports methods
+    NS_DECL_ISUPPORTS
+
+    // nsIBaseStream methods
+    NS_DECL_NSIBASESTREAM
+
+    // nsIInputStream methods
+    NS_DECL_NSIINPUTSTREAM
+
+    // nsIBinaryInputStream methods
+    NS_DECL_NSIBINARYINPUTSTREAM
+    
+protected:
+    nsCOMPtr<nsIInputStream> mInputStream;
+};
+

xpcom/io/nsIBinaryInputStream.idl

@@ -0,0 +1,85 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * The contents of this file are subject to the Netscape Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/NPL/
+ *  
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *  
+ * The Original Code is Mozilla Communicator client code, released
+ * March 31, 1998.
+ * 
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation. Portions created by Netscape are
+ * Copyright (C) 1998-1999 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ */
+
+[ptr] native nsString(nsString); 
+%{ C++
+#include "nsString.h"
+%}
+
+#include "nsIOutputStream.idl"
+#include "nsrootidl.idl"
+
+/**
+ * This interface allows consumption of primitive data types from a "binary
+ * stream" containing untagged, big-endian binary data, i.e. as produced by an
+ * implementation of nsIBinaryOutputStream.  This might be used, for example,
+ * to implement network protocols or to read from architecture-neutral disk
+ * files, i.e. ones that can be read and written by both big-endian and
+ * little-endian platforms.
+ *
+ * @See nsIBinaryOutputStream
+ */
+
+[scriptable, uuid(7b456cb0-8772-11d3-90cf-0040056a906e)]
+interface nsIBinaryInputStream : nsIInputStream {
+    void setInputStream(in nsIInputStream aInputStream);
+    
+    PRBool readBoolean();
+
+    PRUint8 read8();
+    PRUint16 read16();
+    PRUint32 read32();
+    PRUint64 read64();
+
+    float readFloat();
+    double readDouble();
+
+    /**
+     * Read a NUL-terminated 8-bit char* string from a binary stream.
+     */
+    string readStringZ();
+
+    /**
+     * Read a NUL-terminated 16-bit PRUnichar* string from a binary stream.
+     */
+    wstring readWStringZ();
+
+    /**
+     * Read a NUL-terminated UTF8-encoded string from a binary stream, producing
+     * a NUL-terminated 16-bit PRUnichar* string argument as a result.
+     */
+    wstring readUtf8Z();
+
+    /**
+     * Read an opaque byte array from a binary stream.
+     */
+    void readBytes([size_is(aLength)] out string aString, in PRUint32 aLength);
+
+    /**
+     * Read a string (possibly containing embedded NULs) from a binary stream.
+     */
+    [noscript] nsString readString();
+};
+
+%{C++
+NS_COM nsresult
+NS_NewBinaryInputStream(nsIBinaryInputStream* *aResult, nsIInputStream* aSrcStream);
+%}

xpcom/io/nsIBinaryOutputStream.idl

@@ -0,0 +1,86 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * The contents of this file are subject to the Netscape Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/NPL/
+ *  
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *  
+ * The Original Code is Mozilla Communicator client code, released
+ * March 31, 1998.
+ * 
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation. Portions created by Netscape are
+ * Copyright (C) 1998-1999 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ */
+
+[ptr] native nsString(nsString); 
+%{ C++
+#include "nsString.h"
+%}
+
+#include "nsIOutputStream.idl"
+#include "nsrootidl.idl"
+
+/**
+ * This interface allows writing of primitive data types (integers,
+ * floating-point values, booleans, etc.) to a stream in a binary, untagged,
+ * fixed-endianness format.  This might be used, for example, to implement
+ * network protocols or to produce architecture-neutral binary disk files,
+ * i.e. ones that can be read and written by both big-endian and little-endian
+ * platforms.  Output is written in big-endian order (high-order byte first),
+ * as this is traditional network order.
+ *
+ * @See nsIBinaryInputStream
+ */
+
+[scriptable, uuid(204ee610-8765-11d3-90cf-0040056a906e)]
+interface nsIBinaryOutputStream : nsIOutputStream {
+    void setOutputStream(in nsIOutputStream aOutputStream);
+    
+    void writeBoolean(in PRBool aBoolean);
+
+    void write8(in PRUint8 aByte);
+    void write16(in PRUint16 a16);
+    void write32(in PRUint32 a32);
+    void write64(in PRUint64 a64);
+
+    void writeFloat(in float aFloat);
+    void writeDouble(in double aDouble);
+
+    /**
+     * Write a NUL-terminated 8-bit char* string to a binary stream.
+     */
+    void writeStringZ(in string aString);
+
+    /**
+     * Write a NUL-terminated 16-bit PRUnichar* string to a binary stream.
+     */
+    void writeWStringZ(in wstring aString);
+
+    /**
+     * Write a NUL-terminated UTF8-encoded string to a binary stream, produced
+     * from a NUL-terminated 16-bit PRUnichar* string argument.
+     */
+    void writeUtf8Z(in wstring aString);
+
+    /**
+     * Write an opaque byte array to a binary stream.
+     */
+    void writeBytes([size_is(aLength)] in string aString, in PRUint32 aLength);
+
+    /**
+     * Write a string (possibly containing embedded NULs) to a binary stream.
+     */
+    [noscript] void writeString(in nsString aString);
+};
+
+%{C++
+NS_COM nsresult
+NS_NewBinaryOutputStream(nsIBinaryOutputStream* *aResult, nsIOutputStream* aDestStream);
+%}

xpcom/io/nsSegmentedBuffer.cpp

@@ -125,6 +125,32 @@ nsSegmentedBuffer::DeleteFirstSegment()
     }
 }
 
+PRBool
+nsSegmentedBuffer::DeleteLastSegment()
+{
+    PRInt32 last = ModSegArraySize(mLastSegmentIndex - 1);
+    NS_ASSERTION(mSegmentArray[last] != nsnull, "deleting bad segment");
+    (void)mSegAllocator->Free(mSegmentArray[last]);
+    mSegmentArray[last] = nsnull;
+    mLastSegmentIndex = last;
+    return (PRBool)(mLastSegmentIndex == mFirstSegmentIndex);
+}
+
+PRBool
+nsSegmentedBuffer::ReallocLastSegment(size_t newSize)
+{
+    PRInt32 last = ModSegArraySize(mLastSegmentIndex - 1);
+    NS_ASSERTION(mSegmentArray[last] != nsnull, "realloc'ing bad segment");
+    char *newSegment =
+        (char*)mSegAllocator->Realloc(mSegmentArray[last], newSize);
+    if (newSegment) {
+        mSegmentArray[last] = newSegment;
+        return PR_TRUE;
+    } else {
+        return PR_FALSE;
+    }
+}
+
 void
 nsSegmentedBuffer::Empty()
 {

xpcom/io/nsSegmentedBuffer.h

@@ -40,6 +40,13 @@ public:
     // returns true if no more segments remain:
     PRBool DeleteFirstSegment();  // pops from beginning
 
+    // returns true if no more segments remain:
+    PRBool DeleteLastSegment();  // pops from beginning
+
+    // Call Realloc() on last segment.  This is used to reduce memory
+    // consumption when data is not an exact multiple of segment size.
+    PRBool ReallocLastSegment(size_t newSize);
+
     void Empty();               // frees all segments
 
     PRUint32 GetSegmentCount() {
@@ -68,7 +75,7 @@ protected:
         return result;
     }
 
-    PRBool IsFull() {
+   PRBool IsFull() {
         return ModSegArraySize(mLastSegmentIndex + 1) == mFirstSegmentIndex;
     }