Use KeyedCoding as a persistent storage mechanism for blobs

[Brady Eidson]

Use KeyedCoding as a persistent storage mechanism for blobs

This is needed to support https://bugs.webkit.org/show_bug.cgi?id=127011 and other future IDB work.

Anders says he has KeyedEncoding done and KeyedDecoding partially/almost done with a patch at home.  I hope to take over finishing that asap.

[Brady Eidson]

In Radar as <rdar://problem/15818481>

[Brady Eidson]

Created attachment 221323 [details]
Patch v1

[WebKit Commit Bot]

Attachment 221323 [details] did not pass style-queue:

Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/WebCore/ChangeLog', u'Source/WebCore/Modules/indexeddb/IDBKeyPath.cpp', u'Source/WebCore/Modules/indexeddb/IDBKeyPath.h', u'Source/WebCore/WebCore.exp.in', u'Source/WebCore/platform/KeyedCoding.h', u'Source/WebKit2/ChangeLog', u'Source/WebKit2/DatabaseProcess/IndexedDB/IDBSerialization.cpp', u'Source/WebKit2/DatabaseProcess/IndexedDB/IDBSerialization.h', u'Source/WebKit2/DatabaseProcess/IndexedDB/sqlite/UniqueIDBDatabaseBackingStoreSQLite.cpp', u'Source/WebKit2/Shared/cf/KeyedDecoder.cpp', u'Source/WebKit2/Shared/cf/KeyedDecoder.h', u'Source/WebKit2/Shared/cf/KeyedEncoder.cpp', u'Source/WebKit2/Shared/cf/KeyedEncoder.h', u'Source/WebKit2/WebKit2.xcodeproj/project.pbxproj', '--commit-queue']" exit_code: 1
ERROR: Source/WebCore/Modules/indexeddb/IDBKeyPath.cpp:286:  Place brace on its own line for function definitions.  [whitespace/braces] [4]
ERROR: Source/WebCore/Modules/indexeddb/IDBKeyPath.cpp:301:  Place brace on its own line for function definitions.  [whitespace/braces] [4]
Total errors found: 2 in 14 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Anders Carlsson]

Comment on attachment 221323 [details]
Patch v1

View in context: https://bugs.webkit.org/attachment.cgi?id=221323&action=review

> Source/WebCore/platform/KeyedCoding.h:79
> +        while (beginArrayElement()) {

If beginArrayElement() returns false result will be uninitialized. I'd initialize result to true and change the loop to

while (true) { if (!beginArrayElement()) { result = false; break; }

> Source/WebCore/platform/KeyedCoding.h:81
> +            objects.append(T());
> +            result = function(*this, objects.last());

Instead of appending to the array do something like:
T element;
if (!function(*this, t)) {
    result = false;
    break;
}

object.append(std::move(element));

> Source/WebCore/platform/KeyedCoding.h:115
> +    virtual PassRefPtr<SharedBuffer> createBuffer() = 0;

Let's call this finishEncoding() instead to indicate that it can only be called when you're done.

> Source/WebKit2/ChangeLog:7
> +

Extra newline.

[Brady Eidson]

(In reply to comment #4)
> (From update of attachment 221323 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=221323&action=review
> 
> > Source/WebCore/platform/KeyedCoding.h:79
> > +        while (beginArrayElement()) {
> 
> If beginArrayElement() returns false result will be uninitialized. I'd initialize result to true and change the loop to
> 
> while (true) { if (!beginArrayElement()) { result = false; break; }
> 

`result` is only about the success of the individual object function.  It's okay for beginArrayElement to return false, as that just means there's no more elements in the array.

So it seems the only change needed here is to initialize result to true, indicating that no individual object failed to decode.

> > Source/WebCore/platform/KeyedCoding.h:81
> > +            objects.append(T());
> > +            result = function(*this, objects.last());
> 
> Instead of appending to the array do something like:
> T element;
> if (!function(*this, t)) {
>     result = false;
>     break;
> }
> 
> object.append(std::move(element));
> 

Looks good.

> > Source/WebCore/platform/KeyedCoding.h:115
> > +    virtual PassRefPtr<SharedBuffer> createBuffer() = 0;
> 
> Let's call this finishEncoding() instead to indicate that it can only be called when you're done.

Sounds good.

[Brady Eidson]

http://trac.webkit.org/changeset/162148

[Brady Eidson]

http://trac.webkit.org/changeset/162151 as a build fix.

[Darin Adler]

Comment on attachment 221323 [details]
Patch v1

View in context: https://bugs.webkit.org/attachment.cgi?id=221323&action=review

> Source/WebKit2/Shared/cf/KeyedDecoder.h:51
> +    virtual bool decodeInt64(const String& key, int64_t&);
> +    virtual bool decodeUInt32(const String& key, uint32_t&);
> +    virtual bool decodeString(const String& key, String&);
> +
> +    virtual bool beginObject(const String& key);
> +    virtual void endObject();
> +
> +    virtual bool beginArray(const String& key);
> +    virtual bool beginArrayElement();
> +    virtual void endArrayElement();
> +    virtual void endArray();

Should add "override" to all of these.