On Mon, 7 Jul 2025 10:41:58 GMT, Volkan Yazici <[email protected]> wrote:
>> Adds a new `ofFileChannel(FileChannel channel, long offset, long length)`
>> method to `java.net.HttpRequest.BodyPublishers` to provide an `HttpClient`
>> publisher to upload a certain region of a file. The new publisher does not
>> modify the state of the passed `FileChannel`, streams the file channel bytes
>> as it publishes (i.e., avoids reading the entire file into the memory), and
>> can be leveraged to implement sliced uploads. As noted in the Javadoc:
>>
>>> The file channel will not be closed upon completion. The caller is
>>> expected to manage the life cycle of the channel, and close it
>>> appropriately when not needed anymore.
>>
>> ### Implementation notes
>>
>> - `FileChannel` is preferred over `{Readable,Seekable}ByteChannel`, since
>> the latter does not provide a positional read without modifying the state of
>> the `FileChannel`, which is necessary to use a single `FileChannel` instance
>> to implement sliced uploads.
>> - `ofFileChannel(FileChannel,long,long)` is preferred over
>> `ofPath(Path,long,long)` to avoid overloading the maximum file descriptor
>> limit of the platform.
>
> Volkan Yazici has updated the pull request incrementally with one additional
> commit since the last revision:
>
> Improve docs on `IndexOutOfBoundsException` thrown
>
> Co-authored-by: Daniel Fuchs <[email protected]>
src/java.net.http/share/classes/jdk/internal/net/http/RequestPublishers.java
line 490:
> 488: int readLength = channel.read(buffer, position);
> 489: // Short-circuit if `read()` has failed, e.g., due to
> file content being changed in the meantime
> 490: if (readLength < 0) {
The `FileChannel.read(ByteBuffer, position)` API states:
> If the given position is greater than or equal to the file's current size
> then no bytes are read.
I think we might have to consider the situation where the underlying file's
size has reduced and this position is now past that size and the `read()` call
returning 0. Would that then end up in a situation where we have a "never
ending" BodyPublisher, which publishes nothing but hasn't terminated either?
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/26155#discussion_r2213400637
