[qpack] Overhaul the pseudocode

[afrind]

• Use the current terminology (insert count, base, encoder stream)
• Update to current design (modulo encoding of RIC)
• Normalize naming: index vs. idx
• Comments

Fixes #3544

[martinthomson]

I couldn't see any problems, but I have some suggestions.

Thanks for doing the cleanup.

[martinthomson]

Suggested change

	staticIndex = staticTable.getIndex(header)
	staticIndex = staticTable.findIndex(header)

This is a search, right?

[martinthomson]

Suggested change

	dynamicIndex = dynamicTable.getIndex(header)
	dynamicIndex = dynamicTable.findIndex(header)

[martinthomson]

This is a little strange, as you are relying on functions on the tables to find the full entry, but you jump to a different approach for looking up the name. I realize that two lookups are worse than one, but it's an odd stylistic jump, that's all.

# An alternative might be to do the name lookup like this:
staticNameIndex = staticTable.findName(header.name)
if staticNameIndex is None:
    dynamicNameIndex = dynamicTable.findName(header.name)
if header.canIndex() and dynamicTable.canAdd(header):
    encodeInsert(encoderBuffer, staticNameIndex, dynamicNameIndex, header)
    dynamicIndex = dynamicTable.add(header)

    # For a bonus, continuing from the above, forget about the
    # newly inserted dynamic table entry if we are at the limit of blocked streams.
    if numBlockedStreams >= maxBlockedStreams:
        dynamicIndex = None
    else:
        addedBlockingEntry = True
        # Later, you can increase numBlockedStreams, but you only do that once.

[martinthomson]

I can't suggest here, but I think that you just want this:

        dynamicIndex = dynamicTable.add(header)

Otherwise you are breaking encapsulation in a small way: relying on the insert count for getting the index of the thing you just added.

[kazu-yamamoto]

This pseudo code is much better! But I would like to support @martinthomson's comments, too.

[MikeBishop]

Looks good. Your build errors are due to line-length; I think this should fix them.

[MikeBishop]

Suggested change

	# getNameIndex attempts to find an index for this header's name.
	# If one exists, it returns the name's (absolute) index and a
	# getNameIndex searches for this header's name in the table.
	# If an entry matches, it returns the (absolute) index and a

[MikeBishop]

Suggested change

	encodeInsert(encoderBuffer, nameIndex, isStaticName, header)
	encodeInsert(
	encoderBuffer, nameIndex, isStaticName, header
	)

[MikeBishop]

Suggested change

	wireRIC =
	(requiredInsertCount % (2 * getMaxEntries(maxTableCapacity))) + 1;
	wireRIC = (
	requiredInsertCount
	% (2 * getMaxEntries(maxTableCapacity))
	) + 1