# Copyright (C) 2020-2021 all contributors # License: AGPL-3.0+ # temporary stack for public-inbox-index package PublicInbox::IdxStack; use v5.10.1; use strict; use Fcntl qw(:seek); use constant PACK_FMT => eval { pack('Q', 1) } ? 'A1QQH*H*' : 'A1IIH*H*'; # start off in write-only mode sub new { open(my $io, '+>', undef) or die "open: $!"; # latest_cmt is still useful when the newest revision is a `d'(elete), # otherwise we favor $sync->{latest_cmt} for checkpoints and {quit} bless { wr => $io, latest_cmt => $_[1] }, __PACKAGE__ } # file_char = [d|m] sub push_rec { my ($self, $file_char, $at, $ct, $blob_oid, $cmt_oid) = @_; my $rec = pack(PACK_FMT, $file_char, $at, $ct, $blob_oid, $cmt_oid); $self->{unpack_fmt} //= do { my $len = length($cmt_oid); my $fmt = PACK_FMT; $fmt =~ s/H\*/H$len/g; $self->{rec_size} = length($rec); $fmt; }; print { $self->{wr} } $rec or die "print: $!"; $self->{tot_size} += length($rec); } sub num_records { my ($self) = @_; $self->{rec_size} ? $self->{tot_size} / $self->{rec_size} : 0; } # switch into read-only mode and returns self sub read_prepare { my ($self) = @_; my $io = $self->{rd} = delete($self->{wr}); $io->flush or die "flush: $!"; $self; } sub pop_rec { my ($self) = @_; my $sz = $self->{rec_size} or return; my $rec_pos = $self->{tot_size} -= $sz; return if $rec_pos < 0; my $io = $self->{rd}; seek($io, $rec_pos, SEEK_SET) or die "seek: $!"; my $r = read($io, my $buf, $sz); defined($r) or die "read: $!"; $r == $sz or die "read($r != $sz)"; unpack($self->{unpack_fmt}, $buf); } 1;