/* static */ uint32_t
ImageCacheKey::ComputeHash(ImageURL* aURI,
const Maybe<uint64_t>& aBlobSerial,
const PrincipalOriginAttributes& aAttrs,
void* aControlledDocument)
{
// Since we frequently call Hash() several times in a row on the same
// ImageCacheKey, as an optimization we compute our hash once and store it.
nsPrintfCString ptr("%p", aControlledDocument);
nsAutoCString suffix;
aAttrs.CreateSuffix(suffix);
if (aBlobSerial) {
// For blob URIs, we hash the serial number of the underlying blob, so that
// different blob URIs which point to the same blob share a cache entry. We
// also include the ref portion of the URI to support media fragments which
// requires us to create different Image objects even if the source data is
// the same.
nsAutoCString ref;
aURI->GetRef(ref);
return HashGeneric(*aBlobSerial, HashString(ref + suffix + ptr));
}
// For non-blob URIs, we hash the URI spec.
nsAutoCString spec;
aURI->GetSpec(spec);
return HashString(spec + suffix + ptr);
}
static bool
WriteSuffixAndSpec(JSStructuredCloneWriter* aWriter,
const PrincipalOriginAttributes& aAttrs,
const nsCString& aSpec)
{
nsAutoCString suffix;
aAttrs.CreateSuffix(suffix);
return JS_WriteUint32Pair(aWriter, suffix.Length(), aSpec.Length()) &&
JS_WriteBytes(aWriter, suffix.get(), suffix.Length()) &&
JS_WriteBytes(aWriter, aSpec.get(), aSpec.Length());
}