APPENDIX F
1052
Linearized PDF
tables. The tables are reasonably compact and are not designed to be obtained
from the file in random pieces.
The client must now decide whether to continue reading the remainder of the
document sequentially or to abort the initial transaction and access subsequent
pages by using separate transactions requesting byte ranges. This decision is a
function of the size of the file, the data rate of the channel, and the overhead cost
of a transaction.
F.4.2 Opening at an Arbitrary Page
The viewer application may be requested to open a PDF file at an arbitrary page.
The page can be specified in one of three ways:
•
By page number (remote go-to action, integer page specifier)
•
By named destination (remote go-to action, name or string page specifier)
•
By article thread (thread action)
Additionally, an indexed search results in opening a document by page number.
Handling this case efficiently is especially important.
As indicated above, when the document is initially opened, it is retrieved sequen-
tially starting at the beginning. As soon as the hint tables have been received, the
client has sufficient information to request retrieval of any page of the document
given its page number. Therefore, the client can abort the initial transaction and
issue a new transaction for the target page, as described in Section F.4.3, “Going
The position of the primary hint stream (part 5) with respect to the first-page
section (part 6) determines how quickly this can be done. If the primary hint
stream precedes the first-page section, the initial transaction can be aborted very
quickly; however, this is at the cost of increased delay when opening the docu-
ment at the first page. On the other hand, if the primary hint stream follows the
first-page section, displaying the first page is quicker (since the hint tables are not
needed for that), but opening at an arbitrary page is delayed by the time required
to receive the first page. The decision whether to favor opening at the first page or
opening at an arbitrary page must be made at the time a PDF file is linearized.