387044 - Cleanup string usage in nsCSSParser

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect)

Description

[Eli Friedman]

Attachment: Patch

Some small stuff.

Comment 1

[Boris Zbarsky [:bzbarsky]]

So how do .get() and BeginReading() actually differ?  I assume the big win here is the lack of need to call PromiseFlatString() and the lack of a copy in ParseColorString()?

Comment 2

[Eli Friedman]

(In reply to comment #1)
> So how do .get() and BeginReading() actually differ?
The primary difference is that you can only call get() on a string with guaranteed null-terminated storage, i.e. an ns[C]String. They return exactly the same pointer.  The minor difference is that BeginReading returns a const char*.  

> I assume the big win here
> is the lack of need to call PromiseFlatString() and the lack of a copy in
> ParseColorString()?

That's right. PromiseFlatString is probably cheap in this case (just a small stack allocation plus a function call) because we're unlikely to be passing in non-null-terminated strings; however, we don't need it.

Comment 3

[Eli Friedman]

Wait, actually BeginReading involves a function call.  But it's functionally the same for internal strings.

Comment 4

[Eli Friedman]

(In reply to comment #3)
> Wait, actually BeginReading involves a function call.  But it's functionally
> the same for internal strings.

Wait, no, I was right the first time... I got confused by some code that's ifdef'ed out.

Comment 5

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 271136 [details] [diff] [review]
Patch

Oh, BeginReading() is inlined too.  Great.

r+sr=bzbarsky

Comment 6

[Eli Friedman]

Checked in.