gecko/xpcom/io/nsScriptableInputStream.cpp

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#include "nsScriptableInputStream.h"
#include "nsMemory.h"

NS_IMPL_ISUPPORTS1(nsScriptableInputStream, nsIScriptableInputStream)

// nsIBaseStream methods
NS_IMETHODIMP
nsScriptableInputStream::Close(void) {
    if (!mInputStream) return NS_ERROR_NOT_INITIALIZED;
    return mInputStream->Close();
}

// nsIScriptableInputStream methods
NS_IMETHODIMP
nsScriptableInputStream::Init(nsIInputStream *aInputStream) {
    if (!aInputStream) return NS_ERROR_NULL_POINTER;
    mInputStream = aInputStream;
    return NS_OK;
}

NS_IMETHODIMP
nsScriptableInputStream::Available(PRUint32 *_retval) {
    if (!mInputStream) return NS_ERROR_NOT_INITIALIZED;
    return mInputStream->Available(_retval);
}

NS_IMETHODIMP
nsScriptableInputStream::Read(PRUint32 aCount, char **_retval) {
    nsresult rv = NS_OK;
    PRUint32 count = 0;
    char *buffer = nsnull;

    if (!mInputStream) return NS_ERROR_NOT_INITIALIZED;

    rv = mInputStream->Available(&count);
    if (NS_FAILED(rv)) return rv;

    count = PR_MIN(count, aCount);
    buffer = (char*)nsMemory::Alloc(count+1); // make room for '\0'
    if (!buffer) return NS_ERROR_OUT_OF_MEMORY;

    PRUint32 amtRead = 0;
    rv = mInputStream->Read(buffer, count, &amtRead);
    if (NS_FAILED(rv)) {
        nsMemory::Free(buffer);
        return rv;
    }

    buffer[amtRead] = '\0';
    *_retval = buffer;
    return NS_OK;
}

NS_METHOD
nsScriptableInputStream::Create(nsISupports *aOuter, REFNSIID aIID, void **aResult) {
    if (aOuter) return NS_ERROR_NO_AGGREGATION;

    nsScriptableInputStream *sis = new nsScriptableInputStream();
    if (!sis) return NS_ERROR_OUT_OF_MEMORY;

    NS_ADDREF(sis);
    nsresult rv = sis->QueryInterface(aIID, aResult);
    NS_RELEASE(sis);
    return rv;
}