From 1abbc47c045770476f5f9a57c58989d13290d51b Mon Sep 17 00:00:00 2001 From: David Kalnischkies Date: Sat, 17 Dec 2011 17:31:47 +0100 Subject: keep track of where we are in a filedescriptor so we can use it as Tell() information if we are working on a pipe which can't seek --- apt-pkg/contrib/fileutl.cc | 39 ++++++++++++++++++++++++++++++--------- 1 file changed, 30 insertions(+), 9 deletions(-) (limited to 'apt-pkg/contrib/fileutl.cc') diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc index a98c2cb85..bb836e93b 100644 --- a/apt-pkg/contrib/fileutl.cc +++ b/apt-pkg/contrib/fileutl.cc @@ -75,7 +75,9 @@ class FileFdPrivate { bool pipe; APT::Configuration::Compressor compressor; unsigned int openmode; - FileFdPrivate() : gz(NULL), compressed_fd(-1), compressor_pid(-1), pipe(false) {}; + unsigned long long seekpos; + FileFdPrivate() : gz(NULL), compressed_fd(-1), compressor_pid(-1), pipe(false), + openmode(0), seekpos(0) {}; }; // RunScripts - Run a set of scripts from a configuration subtree /*{{{*/ @@ -1065,6 +1067,7 @@ bool FileFd::Read(void *To,unsigned long long Size,unsigned long long *Actual) To = (char *)To + Res; Size -= Res; + d->seekpos += Res; if (Actual != 0) *Actual += Res; } @@ -1134,6 +1137,7 @@ bool FileFd::Write(const void *From,unsigned long long Size) From = (char *)From + Res; Size -= Res; + d->seekpos += Res; } while (Res > 0 && Size > 0); @@ -1151,6 +1155,13 @@ bool FileFd::Seek(unsigned long long To) { if (d->pipe == true) { + // Our poor man seeking in pipes is costly, so try to avoid it + unsigned long long seekpos = Tell(); + if (seekpos == To) + return true; + else if (seekpos < To) + return Skip(To - seekpos); + if ((d->openmode & ReadOnly) != ReadOnly) return _error->Error("Reopen is only implemented for read-only files!"); close(iFd); @@ -1173,6 +1184,8 @@ bool FileFd::Seek(unsigned long long To) if (To != 0) return Skip(To); + + d->seekpos = To; return true; } int res; @@ -1187,7 +1200,8 @@ bool FileFd::Seek(unsigned long long To) Flags |= Fail; return _error->Error("Unable to seek to %llu", To); } - + + d->seekpos = To; return true; } /*}}}*/ @@ -1208,7 +1222,8 @@ bool FileFd::Skip(unsigned long long Over) Flags |= Fail; return _error->Error("Unable to seek ahead %llu",Over); } - + d->seekpos = res; + return true; } /*}}}*/ @@ -1236,6 +1251,13 @@ bool FileFd::Truncate(unsigned long long To) /* */ unsigned long long FileFd::Tell() { + // In theory, we could just return seekpos here always instead of + // seeking around, but not all users of FileFd use always Seek() and co + // so d->seekpos isn't always true and we can just use it as a hint if + // we have nothing else, but not always as an authority… + if (d->pipe == true) + return d->seekpos; + off_t Res; #if APT_USE_ZLIB if (d->gz != NULL) @@ -1245,6 +1267,7 @@ unsigned long long FileFd::Tell() Res = lseek(iFd,0,SEEK_CUR); if (Res == (off_t)-1) _error->Errno("lseek","Failed to determine the current file position"); + d->seekpos = Res; return Res; } /*}}}*/ @@ -1281,15 +1304,14 @@ unsigned long long FileFd::Size() // so we 'read' the content and 'seek' back - see there if (d->pipe == true) { - // FIXME: If we have read first and then FileSize() the report is wrong - size = 0; + unsigned long long const oldSeek = Tell(); char ignore[1000]; unsigned long long read = 0; do { Read(ignore, sizeof(ignore), &read); - size += read; } while(read != 0); - Seek(0); + size = Tell(); + Seek(oldSeek); } #if APT_USE_ZLIB // only check gzsize if we are actually a gzip file, just checking for @@ -1301,7 +1323,6 @@ unsigned long long FileFd::Size() * this ourselves; the original (uncompressed) file size is the last 32 * bits of the file */ // FIXME: Size for gz-files is limited by 32bit… no largefile support - off_t orig_pos = lseek(iFd, 0, SEEK_CUR); if (lseek(iFd, -4, SEEK_END) < 0) return _error->Errno("lseek","Unable to seek to end of gzipped file"); size = 0L; @@ -1315,7 +1336,7 @@ unsigned long long FileFd::Size() size = tmp_size; #endif - if (lseek(iFd, orig_pos, SEEK_SET) < 0) + if (lseek(iFd, d->seekpos, SEEK_SET) < 0) return _error->Errno("lseek","Unable to seek in gzipped file"); return size; } -- cgit v1.2.3 From 40468850491c4f5bc7060763a6f03cdc570d514e Mon Sep 17 00:00:00 2001 From: David Kalnischkies Date: Sun, 18 Dec 2011 01:21:20 +0100 Subject: usage of Skipping in pipes can't work, so we ignore-read instead Also, read only one char in each step of ReadLine instead of back-"seeking" --- apt-pkg/contrib/fileutl.cc | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) (limited to 'apt-pkg/contrib/fileutl.cc') diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc index bb836e93b..b350973af 100644 --- a/apt-pkg/contrib/fileutl.cc +++ b/apt-pkg/contrib/fileutl.cc @@ -1100,15 +1100,19 @@ char* FileFd::ReadLine(char *To, unsigned long long const Size) #endif unsigned long long read = 0; - if (Read(To, Size, &read) == false) + while ((Size - 1) != read) + { + unsigned long long done = 0; + if (Read(To + read, 1, &done) == false) + return NULL; + if (done == 0) + break; + if (To[read++] == '\n') + break; + } + if (read == 0) return NULL; - char* c = To; - for (; *c != '\n' && *c != '\0' && read != 0; --read, ++c) - ; // find the end of the line - if (*c != '\0') - *c = '\0'; - if (read != 0) - Seek(Tell() - read); + To[read] = '\0'; return To; } /*}}}*/ @@ -1210,6 +1214,20 @@ bool FileFd::Seek(unsigned long long To) /* */ bool FileFd::Skip(unsigned long long Over) { + if (d->pipe == true) + { + d->seekpos += Over; + char buffer[1024]; + while (Over != 0) + { + unsigned long long toread = std::min((unsigned long long) sizeof(buffer), Over); + if (Read(buffer, toread) == false) + return _error->Error("Unable to seek ahead %llu",Over); + Over -= toread; + } + return true; + } + int res; #if APT_USE_ZLIB if (d->gz != NULL) -- cgit v1.2.3