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… | |
| 451 | The number of active connections. This is not the number of |
451 | The number of active connections. This is not the number of |
| 452 | currently running requests, but the number of currently open and |
452 | currently running requests, but the number of currently open and |
| 453 | non-idle TCP connections. This number can be useful for |
453 | non-idle TCP connections. This number can be useful for |
| 454 | load-leveling. |
454 | load-leveling. |
| 455 | |
455 | |
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456 | SHOWCASE |
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457 | This section contaisn some more elaborate "real-world" examples or code |
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458 | snippets. |
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459 | |
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460 | HTTP/1.1 FILE DOWNLOAD |
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461 | Downloading files with HTTP cna be quite tricky, especially when |
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462 | something goes wrong and you want tor esume. |
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463 | |
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464 | Here is a function that initiates and resumes a download. It uses the |
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465 | last modified time to check for file content changes, and works with |
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466 | many HTTP/1.0 servers as well, and usually falls back to a complete |
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467 | re-download on older servers. |
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468 | |
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469 | It calls the completion callback with either "undef", which means a |
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470 | nonretryable error occured, 0 when the download was partial and should |
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471 | be retried, and 1 if it was successful. |
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472 | |
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473 | use AnyEvent::HTTP; |
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474 | |
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475 | sub download($$$) { |
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476 | my ($url, $file, $cb) = @_; |
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477 | |
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478 | open my $fh, "+<", $file |
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479 | or die "$file: $!"; |
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480 | |
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481 | my %hdr; |
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482 | my $ofs = 0; |
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483 | |
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484 | warn stat $fh; |
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485 | warn -s _; |
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486 | if (stat $fh and -s _) { |
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487 | $ofs = -s _; |
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488 | warn "-s is ", $ofs;#d# |
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489 | $hdr{"if-unmodified-since"} = AnyEvent::HTTP::format_date +(stat _)[9]; |
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490 | $hdr{"range"} = "bytes=$ofs-"; |
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491 | } |
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492 | |
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493 | http_get $url, |
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494 | headers => \%hdr, |
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495 | on_header => sub { |
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496 | my ($hdr) = @_; |
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497 | |
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498 | if ($hdr->{Status} == 200 && $ofs) { |
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499 | # resume failed |
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500 | truncate $fh, $ofs = 0; |
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501 | } |
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502 | |
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503 | sysseek $fh, $ofs, 0; |
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504 | |
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505 | 1 |
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506 | }, |
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507 | on_body => sub { |
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508 | my ($data, $hdr) = @_; |
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509 | |
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510 | if ($hdr->{Status} =~ /^2/) { |
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511 | length $data == syswrite $fh, $data |
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512 | or return; # abort on write errors |
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513 | } |
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514 | |
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515 | 1 |
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516 | }, |
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517 | sub { |
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518 | my (undef, $hdr) = @_; |
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519 | |
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520 | my $status = $hdr->{Status}; |
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521 | |
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522 | if (my $time = AnyEvent::HTTP::parse_date $hdr->{"last-modified"}) { |
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523 | utime $fh, $time, $time; |
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524 | } |
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525 | |
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526 | if ($status == 200 || $status == 206 || $status == 416) { |
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527 | # download ok || resume ok || file already fully downloaded |
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528 | $cb->(1, $hdr); |
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529 | |
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530 | } elsif ($status == 412) { |
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531 | # file has changed while resuming, delete and retry |
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532 | unlink $file; |
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533 | $cb->(0, $hdr); |
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534 | |
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535 | } elsif ($status == 500 or $status == 503 or $status =~ /^59/) { |
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536 | # retry later |
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537 | $cb->(0, $hdr); |
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538 | |
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539 | } else { |
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540 | $cb->(undef, $hdr); |
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541 | } |
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542 | } |
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543 | ; |
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544 | } |
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545 | |
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546 | download "http://server/somelargefile", "/tmp/somelargefile", sub { |
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547 | if ($_[0]) { |
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548 | print "OK!\n"; |
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549 | } elsif (defined $_[0]) { |
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550 | print "please retry later\n"; |
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551 | } else { |
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552 | print "ERROR\n"; |
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553 | } |
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554 | }; |
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555 | |
| 456 | SOCKS PROXIES |
556 | SOCKS PROXIES |
| 457 | Socks proxies are not directly supported by AnyEvent::HTTP. You can |
557 | Socks proxies are not directly supported by AnyEvent::HTTP. You can |
| 458 | compile your perl to support socks, or use an external program such as |
558 | compile your perl to support socks, or use an external program such as |
| 459 | socksify (dante) or tsocks to make your program use a socks proxy |
559 | socksify (dante) or tsocks to make your program use a socks proxy |
| 460 | transparently. |
560 | transparently. |
| 461 | |
561 | |
