压缩解压

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C/C++

manual.ps：源码内容

Fl(.)150 808 y(F)-8 b(or)36 b(general)e(bac)m(kground)h(information,)f
(particularly)f(ab)s(out)h(memory)h(use)f(and)g(p)s(erformance)g(as-)
150 917 y(p)s(ects,)d(y)m(ou'd)f(b)s(e)g(w)m(ell)f(advised)g(to)j(read)
e(Chapter)g(2)g(as)h(w)m(ell.)150 1218 y Fk(3.1)68 b(T)-11
b(op-lev)l(el)46 b(structure)150 1411 y Fj(libbzip2)33
b Fl(is)i(a)h(15exible)e(library)f(for)j(compressing)f(and)g
(decompressing)f(data)j(in)d(the)i Fj(bzip2)e Fl(data)150
1520 y(format.)39 b(Although)24 b(pac)m(k)-5 b(aged)26
b(as)e(a)h(single)e(en)m(tit)m(y)-8 b(,)27 b(it)d(helps)f(to)i(regard)g
(the)g(library)d(as)i(three)h(separate)150 1630 y(parts:)40
b(the)31 b(lo)m(w)f(lev)m(el)g(in)m(terface,)h(and)f(the)h(high)e(lev)m
(el)h(in)m(terface,)h(and)f(some)h(utilit)m(y)d(functions.)150
1787 y(The)38 b(structure)g(of)g Fj(libbzip2)p Fl('s)e(in)m(terfaces)j
(is)e(similar)f(to)j(that)g(of)g(Jean-loup)e(Gailly's)g(and)h(Mark)150
1896 y(Adler's)29 b(excellen)m(t)i Fj(zlib)e Fl(library)-8
b(.)150 2157 y Ff(3.1.1)63 b(Lo)m(w-lev)m(el)39 b(summary)150
2349 y Fl(This)21 b(in)m(terface)h(pro)m(vides)g(services)g(for)g
(compressing)f(and)h(decompressing)f(data)i(in)e(memory)-8
b(.)38 b(There's)150 2459 y(no)43 b(pro)m(vision)e(for)h(dealing)g
(with)f(14les,)k(streams)e(or)g(an)m(y)g(other)g(I/O)g(mec)m
(hanisms,)i(just)e(straigh)m(t)150 2568 y(memory-to-memory)25
b(w)m(ork.)38 b(In)23 b(fact,)k(this)22 b(part)i(of)f(the)h(library)d
(can)j(b)s(e)f(compiled)f(without)h(inclusion)150 2678
y(of)31 b Fj(stdio.h)p Fl(,)d(whic)m(h)h(ma)m(y)i(b)s(e)f(helpful)d
(for)k(em)m(b)s(edded)e(applications.)150 2835 y(The)h(lo)m(w-lev)m(el)
g(part)g(of)h(the)f(library)e(has)i(no)h(global)e(v)-5
b(ariables)29 b(and)h(is)g(therefore)g(thread-safe.)150
2992 y(Six)f(routines)g(mak)m(e)j(up)d(the)i(lo)m(w)f(lev)m(el)g(in)m
(terface:)41 b Fj(bzCompressInit)p Fl(,)27 b Fj(bzCompress)p
Fl(,)h(and)150 3101 y Fj(bzCompressEnd)f Fl(for)j(compression,)g(and)f
(a)i(corresp)s(onding)d(trio)i Fj(bzDecompressInit)p
Fl(,)150 3211 y Fj(bzDecompress)41 b Fl(and)k Fj(bzDecompressEnd)40
b Fl(for)45 b(decompression.)83 b(The)44 b Fj(*Init)f
Fl(functions)g(allo)s(cate)150 3321 y(memory)31 b(for)g
(compression/decompression)e(and)i(do)g(other)g(initialisations,)d
(whilst)h(the)j Fj(*End)e Fl(func-)150 3430 y(tions)g(close)g(do)m(wn)g
(op)s(erations)g(and)g(release)g(memory)-8 b(.)150 3587
y(The)23 b(real)g(w)m(ork)h(is)f(done)g(b)m(y)g Fj(bzCompress)e
Fl(and)i Fj(bzDecompress)p Fl(.)35 b(These)24 b(compress/decompress)f
(data)150 3697 y(from)i(a)g(user-supplied)d(input)h(bu13er)h(to)i(a)g
(user-supplied)c(output)i(bu13er.)38 b(These)25 b(bu13ers)f(can)i
(b)s(e)f(an)m(y)150 3806 y(size;)35 b(arbitrary)d(quan)m(tities)g(of)i
(data)f(are)h(handled)d(b)m(y)i(making)g(rep)s(eated)g(calls)g(to)g
(these)h(functions.)150 3916 y(This)f(is)h(a)i(15exible)d(mec)m
(hanism)i(allo)m(wing)f(a)h(consumer-pull)d(st)m(yle)k(of)f(activit)m
(y)-8 b(,)37 b(or)f(pro)s(ducer-push,)150 4025 y(or)30
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(vides)e(some)h(handy)f(wrapp)s(ers)f(around)h(the)i(lo)m(w-lev)m(el)f
(in)m(terface)g(to)h(facilitate)150 4588 y(reading)26
b(and)g(writing)f Fj(bzip2)g Fl(format)i(14les)f(()p
Fj(.bz2)g Fl(14les).)38 b(The)27 b(routines)e(pro)m(vide)h(ho)s(oks)
h(to)g(facilitate)150 4698 y(reading)43 b(14les)f(in)h(whic)m(h)f
(the)i Fj(bzip2)f Fl(data)h(stream)g(is)f(em)m(b)s(edded)f(within)g
(some)i(larger-scale)g(14le)150 4807 y(structure,)30
b(or)h(where)e(there)i(are)g(m)m(ultiple)d Fj(bzip2)h
Fl(data)i(streams)f(concatenated)j(end-to-end.)150 4964
y(F)-8 b(or)36 b(reading)e(14les,)i Fj(bzReadOpen)p
Fl(,)e Fj(bzRead)p Fl(,)h Fj(bzReadClose)d Fl(and)i Fj(bzReadGetUnused)
d Fl(are)36 b(supplied.)150 5074 y(F)-8 b(or)31 b(writing)e(14les,)g
Fj(bzWriteOpen)p Fl(,)f Fj(bzWrite)g Fl(and)i Fj(bzWriteFinish)d
Fl(are)j(a)m(v)-5 b(ailable.)150 5230 y(As)24 b(with)f(the)h(lo)m
(w-lev)m(el)h(library)-8 b(,)23 b(no)h(global)g(v)-5
b(ariables)23 b(are)h(used)g(so)g(the)h(library)c(is)j(p)s(er)f(se)h
(thread-safe.)150 5340 y(Ho)m(w)m(ev)m(er,)32 b(if)c(I/O)h(errors)g(o)s
(ccur)g(whilst)e(reading)i(or)g(writing)e(the)j(underlying)c
(compressed)j(14les,)g(y)m(ou)p eop
%%Page: 12 13
12 12 bop 150 -116 a Fl(Chapter)30 b(3:)41 b(Programming)29
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b(ha)m(v)m(e)g(to)g(consult)e Fj(errno)g Fl(to)h(determine)g(the)g
(cause)g(of)h(the)f(error.)42 b(In)30 b(that)i(case,)h(y)m(ou'd)e(need)
g(a)150 476 y(C)f(library)e(whic)m(h)h(correctly)i(supp)s(orts)d
Fj(errno)h Fl(in)g(a)i(m)m(ultithreaded)e(en)m(vironmen)m(t.)150
633 y(T)-8 b(o)44 b(mak)m(e)h(the)f(library)d(a)j(little)f(simpler)e
(and)j(more)g(p)s(ortable,)i Fj(bzReadOpen)41 b Fl(and)i
Fj(bzWriteOpen)150 742 y Fl(require)20 b(y)m(ou)h(to)h(pass)e(them)h
(14le)f(handles)f(()p Fj(FILE*)p Fl(s))h(whic)m(h)g(ha)m(v)m(e)i
(previously)d(b)s(een)h(op)s(ened)g(for)h(reading)150
852 y(or)j(writing)d(resp)s(ectiv)m(ely)-8 b(.)39 b(That)23
b(a)m(v)m(oids)h(p)s(ortabilit)m(y)e(problems)g(asso)s(ciated)i(with)f
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(needs,)49 b Fj(bzBuffToBuffCompress)40 b Fl(and)45 b
Fj(bzBuffToBuffDecompress)39 b Fl(are)46 b(pro-)150 1504
y(vided.)37 b(These)23 b(compress)f(data)i(in)e(memory)h(from)f(one)i
(bu13er)e(to)h(another)g(bu13er)f(in)g(a)i(single)d(function)150
1614 y(call.)60 b(Y)-8 b(ou)37 b(should)e(assess)j(whether)e(these)h
(functions)f(ful14ll)d(y)m(our)k(memory-to-memory)i(compres-)150
1723 y(sion/decompression)28 b(requiremen)m(ts)g(b)s(efore)g(in)m(v)m
(esting)h(e13ort)h(in)e(understanding)e(the)k(more)f(general)150
1833 y(but)h(more)g(complex)g(lo)m(w-lev)m(el)g(in)m(terface.)150
1990 y(Y)-8 b(oshiok)j(a)47 b(Tsuneo)e(()p Fj
(QWF00133@niftyserve.or.jp)40 b Fl(/)46 b Fj(tsuneo-y@is.aist-nara.ac.)
o(jp)p Fl())40 b(has)150 2099 y(con)m(tributed)30 b(some)h(functions)e
(to)i(giv)m(e)g(b)s(etter)f Fj(zlib)g Fl(compatibilit)m(y)-8
b(.)39 b(These)31 b(functions)e(are)h Fj(bzopen)p Fl(,)150
2209 y Fj(bzread)p Fl(,)43 b Fj(bzwrite)p Fl(,)f Fj(bzflush)p
Fl(,)g Fj(bzclose)p Fl(,)g Fj(bzerror)e Fl(and)g Fj(bzlibVersion)p
Fl(.)70 b(Y)-8 b(ou)42 b(ma)m(y)g(14nd)d(these)150
2318 y(functions)31 b(more)i(con)m(v)m(enien)m(t)h(for)f(simple)d
(14le)i(reading)g(and)g(writing,)g(than)h(those)g(in)e(the)i
(high-lev)m(el)150 2428 y(in)m(terface.)61 b(These)37
b(functions)e(are)j(not)f((y)m(et))i(o16cially)c(part)i(of)g(the)g
(library)-8 b(,)37 b(and)g(are)g(not)g(further)150 2538
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b(handling)150 3270 y Fl(The)23 b(library)f(is)h(designed)g(to)i(reco)m
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(during)f(decompression)h(if)g(y)m(ou)150 3599 y(are)g(feeling)f(esp)s
(ecially)f(paranoid.)39 b(I)28 b(w)m(ould)g(b)s(e)g(in)m(terested)h(in)
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y(of)i(the)f(library)e(to)j(corrupted)f(compressed)g(data.)150
3865 y(The)25 b(14le)g Fj(bzlib.h)f Fl(con)m(tains)i(all)f
(de14nitions)e(needed)i(to)i(use)e(the)h(library)-8
b(.)37 b(In)26 b(particular,)f(y)m(ou)h(should)150 3975
y(de14nitely)i(not)j(include)d Fj(bzlib_private.h)p
Fl(.)150 4132 y(In)39 b Fj(bzlib.h)p Fl(,)h(the)g(v)-5
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4570 y(situation.)150 4749 y Fj(BZ_OK)240 b Fl(The)30
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b(.)p eop
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g(the)h(error)f(indicator)g((viz,)k Fj(ferror(f))p
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4613 y(op)s(erating-system)30 b(sp)s(eci14c)f(information)g(ab)s(out)
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eop
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Fj(next_in)572 1404 y Fl(to)h Fj(next_out)d Fl(as)j(m)m(uc)m(h)f(as)h
(p)s(ossible,)d(but)i(do)g(not)g(accept)i(an)m(y)f(more)f(input.)572
1508 y(Next)h(state)h(=)e(FLUSHING)572 1612 y(Return)f(v)-5
b(alue)30 b(=)g Fj(BZ_FLUSH_OK)390 1819 y Fl(R)m(UNNING/)p
Fj(BZ_FINISH)572 1923 y Fl(Remem)m(b)s(er)g(curren)m(t)g(v)-5
b(alue)30 b(of)g Fj(next_in)p Fl(.)59 b(Compress)30 b(from)g
Fj(next_in)572 2027 y Fl(to)h Fj(next_out)d Fl(as)j(m)m(uc)m(h)f(as)h
(p)s(ossible,)d(but)i(do)g(not)g(accept)i(an)m(y)f(more)f(input.)572
2131 y(Next)h(state)h(=)e(FINISHING)572 2234 y(Return)f(v)-5
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Fj(BZ_FLUSH)572 2546 y Fl(Compress)f(from)h Fj(next_in)f
Fl(to)i Fj(next_out)d Fl(as)i(m)m(uc)m(h)h(as)f(p)s(ossible,)572
2650 y(but)f(do)i(not)f(accept)i(an)m(y)f(more)f(input.)572
2753 y(If)g(all)f(the)i(existing)e(input)f(has)i(b)s(een)g(used)g(up)f
(and)h(all)f(compressed)572 2857 y(output)h(has)g(b)s(een)g(remo)m(v)m
(ed)663 2961 y(Next)h(state)h(=)e(R)m(UNNING;)i(Return)d(v)-5
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y(Next)h(state)h(=)e(FLUSHING;)h(Return)e(v)-5 b(alue)30
b(=)g Fj(BZ_FLUSH_OK)390 3376 y Fl(FLUSHING/other)572
3480 y(Illegal.)572 3584 y(Return)f(v)-5 b(alue)30 b(=)g
Fj(BZ_SEQUENCE_ERROR)390 3791 y Fl(FINISHING/)p Fj(BZ_FINISH)572
3895 y Fl(Compress)f(from)h Fj(next_in)f Fl(to)i Fj(next_out)d
Fl(as)i(m)m(uc)m(h)h(as)f(p)s(ossible,)572 3999 y(but)f(to)j(not)e
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(input)f(has)i(b)s(een)g(used)g(up)f(and)h(all)f(compressed)572
4206 y(output)h(has)g(b)s(een)g(remo)m(v)m(ed)663 4310
y(Next)h(state)h(=)e(IDLE;)g(Return)g(v)-5 b(alue)30
b(=)g Fj(BZ_STREAM_END)572 4414 y Fl(else)663 4518 y(Next)h(state)h(=)e
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4725 y Fl(FINISHING/other)572 4829 y(Illegal.)572 4933
y(Return)f(v)-5 b(alue)30 b(=)g Fj(BZ_SEQUENCE_ERROR)150
5090 y Fl(That)24 b(still)f(lo)s(oks)g(complicated?)39
b(W)-8 b(ell,)25 b(fair)f(enough.)38 b(The)24 b(usual)f(sequence)i(of)f
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eop
%%Page: 18 19
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b(rivial)28 b(other)j(p)s(ossible)d(return)h(v)-5 b(alues:)572
2052 y Fj(BZ_PARAM_ERROR)663 2156 y Fl(if)29 b Fj(strm)g
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2392 y Ff(3.3.3)63 b Fe(bzCompressEnd)390 2579 y Fj(int)47
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y Fl(Releases)31 b(all)e(memory)h(asso)s(ciated)h(with)e(a)i
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y Ff(3.3.4)63 b Fe(bzDecompressInit)390 3570 y Fj(int)47
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1591 y Ff(3.3.5)63 b Fe(bzDecompress)390 1777 y Fj(int)47
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2577 y(Similarly)-8 b(,)37 b Fj(next_out)f Fl(should)g(p)s(oin)m(t)i
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(to)h(b)s(e)150 2686 y(placed,)23 b(with)d Fj(avail_out)f
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b(ailable.)37 b Fj(bzCompress)19 b Fl(up)s(dates)150
2796 y Fj(next_out)p Fl(,)28 b Fj(avail_out)g Fl(and)i
Fj(total_out)e Fl(to)j(re15ect)g(the)f(n)m(um)m(b)s(er)g(of)g(b)m
(ytes)h(output.)150 2953 y(Y)-8 b(ou)53 b(ma)m(y)h(pro)m(vide)e(and)g
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3438 y(Use)f(of)f Fj(bzDecompress)d Fl(is)j(simpler)e(than)i
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b(App)s(earance)39 b(of)g Fj(BZ_STREAM_END)c Fl(denotes)150
3814 y(that)d Fj(bzDecompress)c Fl(has)k(detected)g(the)g(logical)f
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3924 y Fl(will)18 b(not)k(pro)s(duce)e Fj(BZ_STREAM_END)d
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(the)g(output)g(bu13er,)150 4033 y(so)27 b(once)h Fj(BZ_STREAM_END)23
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4717 y Fj(BZ_PARAM_ERROR)663 4821 y Fl(if)29 b Fj(strm)g
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4925 y Fl(or)h Fj(strm->avail_out)44 b(<)j(1)572 5029
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Fl(should)23 b(b)s(e)i(consulted)g(14rst)g(to)h(determine)e(the)i
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b(not.)79 b(If)43 b(y)m(ou)g(omit)g(this,)i(y)m(ou)f(ma)m(y)f(encoun)m
(ter)h(problems)d(when)330 695 y(mo)m(ving)30 b(co)s(de)h(to)g(new)f
(platforms.)225 858 y Fi(17)60 b Fl(Memory)23 b(allo)s(cation)f
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Fj(free)p Fl(.)36 b(A)m(t)23 b(presen)m(t)g(there)g(is)f(no)h(facilit)m
(y)330 967 y(for)40 b(user-de14ned)e(memory)i(allo)s(cators)g(in)f
(the)h(14le)g(I/O)g(functions)e((could)i(easily)f(b)s(e)g(added,)330
1077 y(though).)150 1379 y Ff(3.4.1)63 b Fe(bzReadOpen)533
1566 y Fj(typedef)46 b(void)h(BZFILE;)533 1773 y(BZFILE)f(*bzReadOpen)f
(()i(int)g(*bzerror,)f(FILE)g(*f,)1535 1877 y(int)h(small,)f(int)h
(verbosity,)1535 1981 y(void)g(*unused,)f(int)h(nUnused)e();)150
2138 y Fl(Prepare)29 b(to)g(read)g(compressed)f(data)i(from)e(14le)g
(handle)f Fj(f)p Fl(.)40 b Fj(f)29 b Fl(should)d(refer)j(to)h(a)f
(14le)f(whic)m(h)f(has)i(b)s(een)150 2247 y(op)s(ened)h(for)h
(reading,)f(and)h(for)f(whic)m(h)g(the)h(error)g(indicator)e(()p
Fj(ferror(f))p Fl()is)f(not)k(set.)42 b(If)31 b Fj(small)e
Fl(is)h(1,)150 2357 y(the)h(library)d(will)f(try)j(to)i(decompress)e
(using)f(less)g(memory)-8 b(,)31 b(at)g(the)g(exp)s(ense)f(of)g(sp)s
(eed.)150 2514 y(F)-8 b(or)26 b(reasons)f(explained)e(b)s(elo)m(w,)j
Fj(bzRead)d Fl(will)g(decompress)i(the)g Fj(nUnused)e
Fl(b)m(ytes)j(starting)f(at)g Fj(unused)p Fl(,)150 2623
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Fj(f)p Fl(.)40 b(A)m(t)30 b(most)g Fj(BZ_MAX_UNUSED)25
b Fl(b)m(ytes)30 b(ma)m(y)g(b)s(e)f(supplied)d(lik)m(e)150
2733 y(this.)53 b(If)34 b(this)g(facilit)m(y)g(is)g(not)h(required,)f
(y)m(ou)h(should)e(pass)h Fj(NULL)g Fl(and)g Fj(0)g Fl(for)h
Fj(unused)e Fl(and)h(n)p Fj(Unused)150 2842 y Fl(resp)s(ectiv)m(ely)-8
b(.)150 2999 y(F)g(or)31 b(the)g(meaning)e(of)i(parameters)g
Fj(small)e Fl(and)g Fj(verbosity)p Fl(,)f(see)j Fj(bzDecompressInit)p
Fl(.)150 3156 y(The)k(amoun)m(t)g(of)g(memory)g(needed)g(to)g
(decompress)g(a)h(14le)e(cannot)h(b)s(e)g(determined)e(un)m(til)h
(the)h(14le's)150 3266 y(header)g(has)g(b)s(een)f(read.)55
b(So)35 b(it)g(is)f(p)s(ossible)f(that)j Fj(bzReadOpen)c
Fl(returns)i Fj(BZ_OK)g Fl(but)g(a)i(subsequen)m(t)150
3375 y(call)30 b(of)g Fj(bzRead)f Fl(will)f(return)h
Fj(BZ_MEM_ERROR)p Fl(.)150 3532 y(P)m(ossible)g(assignmen)m(ts)h(to)h
Fj(bzerror)p Fl(:)572 3683 y Fj(BZ_PARAM_ERROR)663 3787
y Fl(if)e Fj(f)h Fl(is)g Fj(NULL)663 3891 y Fl(or)g Fj(small)f
Fl(is)g(neither)h Fj(0)g Fl(nor)g Fj(1)663 3994 y Fl(or)g
Fj((unused)46 b(==)h(NULL)g(&&)g(nUnused)f(!=)h(0))663
4098 y Fl(or)30 b Fj((unused)46 b(!=)h(NULL)g(&&)g(!(0)g(<=)g
(nUnused)f(<=)h(BZ_MAX_UNUSED)))572 4202 y(BZ_IO_ERROR)663
4306 y Fl(if)29 b Fj(ferror(f))f Fl(is)h(nonzero)572
4409 y Fj(BZ_MEM_ERROR)663 4513 y Fl(if)g(insu16cien)m(t)g(memory)h
(is)f(a)m(v)-5 b(ailable)572 4617 y Fj(BZ_OK)663 4721
y Fl(otherwise.)150 4878 y(P)m(ossible)29 b(return)h(v)-5
b(alues:)572 5029 y(P)m(oin)m(ter)31 b(to)g(an)f(abstract)h
Fj(BZFILE)663 5132 y Fl(if)e Fj(bzerror)f Fl(is)i Fj(BZ_OK)572
5236 y(NULL)663 5340 y Fl(otherwise)p eop
%%Page: 22 23
22 22 bop 150 -116 a Fl(Chapter)30 b(3:)41 b(Programming)29
b(with)g Fj(libbzip2)1881 b Fl(22)150 366 y(Allo)m(w)m(able)30
b(next)g(actions:)572 518 y Fj(bzRead)663 621 y Fl(if)f
Fj(bzerror)f Fl(is)i Fj(BZ_OK)572 725 y(bzClose)663 829
y Fl(otherwise)150 1103 y Ff(3.4.2)63 b Fe(bzRead)533
1290 y Fj(int)47 b(bzRead)f(()i(int)f(*bzerror,)e(BZFILE)h(*b,)h(void)
f(*buf,)h(int)g(len)g();)150 1447 y Fl(Reads)35 b(up)f(to)h
Fj(len)f Fl((uncompressed))h(b)m(ytes)g(from)f(the)h(compressed)g
(14le)f Fj(b)g Fl(in)m(to)h(the)g(bu13er)f Fj(buf)p
Fl(.)53 b(If)150 1556 y(the)30 b(read)f(w)m(as)h(successful,)f
Fj(bzerror)e Fl(is)i(set)h(to)g Fj(BZ_OK)e Fl(and)h(the)h(n)m(um)m(b)s
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Fj(bzerror)31 b Fl(will)g(b)s(e)h(set)i(to)g Fj(BZ_STREAM_END)p
Fl(,)d(and)i(the)150 1776 y(n)m(um)m(b)s(er)c(of)i(b)m(ytes)f(read)h
(is)e(returned.)40 b(All)29 b(other)h Fj(bzerror)f Fl(v)-5
b(alues)29 b(denote)i(an)g(error.)150 1932 y Fj(bzRead)f
Fl(will)e(supply)h Fj(len)h Fl(b)m(ytes,)j(unless)c(the)j(logical)f
(stream)g(end)g(is)f(detected)j(or)e(an)g(error)g(o)s(ccurs.)150
2042 y(Because)22 b(of)f(this,)h(it)f(is)f(p)s(ossible)e(to)k(detect)g
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(um)m(b)s(er)f(requested.)53 b(Nev)m(ertheless,)37 b(this)c(is)g
(regarded)i(as)f(inadvisable;)150 2261 y(y)m(ou)d(should)d(instead)i(c)
m(hec)m(k)i Fj(bzerror)c Fl(after)j(ev)m(ery)g(call)f(and)g(w)m(atc)m
(h)h(out)g(for)f Fj(BZ_STREAM_END)p Fl(.)150 2418 y(In)m(ternally)-8
b(,)37 b Fj(bzRead)d Fl(copies)i(data)h(from)f(the)g(compressed)g
(14le)f(in)g(c)m(h)m(unks)h(of)h(size)f Fj(BZ_MAX_UNUSED)150
2528 y Fl(b)m(ytes)31 b(b)s(efore)e(decompressing)h(it.)40
b(If)29 b(the)i(14le)e(con)m(tains)h(more)h(b)m(ytes)f(than)g
(strictly)f(needed)h(to)h(reac)m(h)150 2637 y(the)26
b(logical)g(end-of-stream,)i Fj(bzRead)c Fl(will)f(almost)j(certainly)g
(read)g(some)g(of)g(the)g(trailing)f(data)h(b)s(efore)150
2747 y(signalling)31 b Fj(BZ_SEQUENCE_END)p Fl(.)45 b(T)-8
b(o)34 b(collect)g(the)f(read)g(but)g(un)m(used)f(data)i(once)g
Fj(BZ_SEQUENCE_END)150 2856 y Fl(has)c(app)s(eared,)g(call)g
Fj(bzReadGetUnused)c Fl(immediately)j(b)s(efore)h Fj(bzReadClose)p
Fl(.)150 3013 y(P)m(ossible)f(assignmen)m(ts)h(to)h Fj(bzerror)p
Fl(:)572 3164 y Fj(BZ_PARAM_ERROR)663 3268 y Fl(if)e
Fj(b)h Fl(is)g Fj(NULL)f Fl(or)h Fj(buf)g Fl(is)f Fj(NULL)g
Fl(or)i Fj(len)46 b(<)i(0)572 3372 y(BZ_SEQUENCE_ERROR)663
3475 y Fl(if)29 b Fj(b)h Fl(w)m(as)h(op)s(ened)e(with)h
Fj(bzWriteOpen)572 3579 y(BZ_IO_ERROR)663 3683 y Fl(if)f(there)i(is)e
(an)h(error)g(reading)g(from)g(the)g(compressed)g(14le)572
3787 y Fj(BZ_UNEXPECTED_EOF)663 3891 y Fl(if)f(the)i(compressed)f
(14le)f(ended)h(b)s(efore)g(the)g(logical)g(end-of-stream)h(w)m(as)g
(detected)572 3994 y Fj(BZ_DATA_ERROR)663 4098 y Fl(if)e(a)i(data)g(in)
m(tegrit)m(y)f(error)g(w)m(as)h(detected)h(in)d(the)h(compressed)g
(stream)572 4202 y Fj(BZ_DATA_ERROR_MAGIC)663 4306 y
Fl(if)f(the)i(stream)f(do)s(es)g(not)h(b)s(egin)e(with)g(the)i
(requisite)e(header)h(b)m(ytes)h((ie,)f(is)g(not)663
4409 y(a)g Fj(bzip2)f Fl(data)i(14le).)61 b(This)28
b(is)i(really)f(a)i(sp)s(ecial)e(case)i(of)g Fj(BZ_DATA_ERROR)p
Fl(.)572 4513 y Fj(BZ_MEM_ERROR)663 4617 y Fl(if)e(insu16cien)m(t)g
(memory)h(w)m(as)h(a)m(v)-5 b(ailable)572 4721 y Fj(BZ_STREAM_END)663
4825 y Fl(if)29 b(the)i(logical)e(end)h(of)h(stream)f(w)m(as)h
(detected.)572 4928 y Fj(BZ_OK)663 5032 y Fl(otherwise.)150
5189 y(P)m(ossible)e(return)h(v)-5 b(alues:)572 5340
y(n)m(um)m(b)s(er)29 b(of)h(b)m(ytes)h(read)p eop
%%Page: 23 24
23 23 bop 150 -116 a Fl(Chapter)30 b(3:)41 b(Programming)29
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Fl(is)i Fj(BZ_OK)f Fl(or)h Fj(BZ_STREAM_END)572 470 y
Fl(unde14ned)663 574 y(otherwise)150 731 y(Allo)m(w)m(able)g(next)g
(actions:)572 882 y(collect)h(data)g(from)f Fj(buf)p
Fl(,)f(then)h Fj(bzRead)f Fl(or)h Fj(bzReadClose)663
986 y Fl(if)f Fj(bzerror)f Fl(is)i Fj(BZ_OK)572 1089
y Fl(collect)h(data)g(from)f Fj(buf)p Fl(,)f(then)h Fj(bzReadClose)e
Fl(or)i Fj(bzReadGetUnused)663 1193 y Fl(if)f Fj(bzerror)f
Fl(is)i Fj(BZ_SEQUENCE_END)572 1297 y(bzReadClose)663
1401 y Fl(otherwise)150 1642 y Ff(3.4.3)63 b Fe(bzReadGetUnused)533
1829 y Fj(void)47 b(bzReadGetUnused)c(()48 b(int*)f(bzerror,)e(BZFILE)
h(*b,)1631 1932 y(void**)g(unused,)g(int*)g(nUnused)g();)150
2089 y Fl(Returns)36 b(data)i(whic)m(h)d(w)m(as)j(read)f(from)f(the)h
(compressed)g(14le)f(but)g(w)m(as)h(not)h(needed)e(to)i(get)g(to)g
(the)150 2199 y(logical)k(end-of-stream.)78 b Fj(*unused)41
b Fl(is)h(set)h(to)g(the)g(address)f(of)g(the)h(data,)k(and)42
b Fj(*nUnused)e Fl(to)k(the)150 2308 y(n)m(um)m(b)s(er)29
b(of)i(b)m(ytes.)41 b Fj(*nUnused)28 b Fl(will)g(b)s(e)h(set)i(to)g(a)g
(v)-5 b(alue)30 b(b)s(et)m(w)m(een)h Fj(0)f Fl(and)g
Fj(BZ_MAX_UNUSED)d Fl(inclusiv)m(e.)150 2465 y(This)40
b(function)h(ma)m(y)h(only)f(b)s(e)h(called)f(once)h
Fj(bzRead)e Fl(has)i(signalled)e Fj(BZ_STREAM_END)e Fl(but)j(b)s(efore)
150 2575 y Fj(bzReadClose)p Fl(.)150 2732 y(P)m(ossible)29
b(assignmen)m(ts)h(to)h Fj(bzerror)p Fl(:)572 2883 y
Fj(BZ_PARAM_ERROR)663 2986 y Fl(if)e Fj(b)h Fl(is)g Fj(NULL)663
3090 y Fl(or)g Fj(unused)f Fl(is)g Fj(NULL)g Fl(or)i
Fj(nUnused)d Fl(is)i Fj(NULL)572 3194 y(BZ_SEQUENCE_ERROR)663
3298 y Fl(if)f Fj(BZ_STREAM_END)e Fl(has)j(not)h(b)s(een)e(signalled)
663 3402 y(or)h(if)f Fj(b)h Fl(w)m(as)h(op)s(ened)f(with)f
Fj(bzWriteOpen)542 3505 y(BZ_OK)663 3609 y Fl(otherwise)150
3766 y(Allo)m(w)m(able)h(next)g(actions:)572 3917 y Fj(bzReadClose)150
4158 y Ff(3.4.4)63 b Fe(bzReadClose)533 4345 y Fj(void)47
b(bzReadClose)e(()i(int)g(*bzerror,)e(BZFILE)h(*b)h();)150
4502 y Fl(Releases)26 b(all)f(memory)g(p)s(ertaining)e(to)k(the)e
(compressed)h(14le)e Fj(b)p Fl(.)39 b Fj(bzReadClose)23
b Fl(do)s(es)i(not)h(call)f Fj(fclose)150 4611 y Fl(on)33
b(the)f(underlying)e(14le)i(handle,)g(so)h(y)m(ou)g(should)d(do)j
(that)g(y)m(ourself)f(if)f(appropriate.)47 b Fj(bzReadClose)150
4721 y Fl(should)28 b(b)s(e)i(called)g(to)h(clean)f(up)f(after)i(all)f
(error)g(situations.)150 4878 y(P)m(ossible)f(assignmen)m(ts)h(to)h
Fj(bzerror)p Fl(:)572 5029 y Fj(BZ_SEQUENCE_ERROR)663
5132 y Fl(if)e Fj(b)h Fl(w)m(as)h(op)s(ened)e(with)h
Fj(bzOpenWrite)572 5236 y(BZ_OK)663 5340 y Fl(otherwise)p
eop
%%Page: 24 25
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(*bzerror,)e(FILE)i(*f,)1583 1057 y(int)g(blockSize100k,)d(int)j
(verbosity,)1583 1160 y(int)g(workFactor)e();)150 1317
y Fl(Prepare)33 b(to)g(write)f(compressed)h(data)h(to)f(14le)f
(handle)g Fj(f)p Fl(.)47 b Fj(f)33 b Fl(should)e(refer)i(to)g(a)g
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1693 y Fj(bzCompressInit)p Fl(.)150 1850 y(All)d(required)f(memory)i
(is)f(allo)s(cated)i(at)g(this)e(stage,)j(so)f(if)e(the)h(call)g
(completes)g(successfully)-8 b(,)26 b Fj(BZ_MEM_)150
1960 y(ERROR)j Fl(cannot)i(b)s(e)f(signalled)e(b)m(y)i(a)h(subsequen)m
(t)f(call)f(to)i Fj(bzWrite)p Fl(.)150 2117 y(P)m(ossible)e(assignmen)m
(ts)h(to)h Fj(bzerror)p Fl(:)572 2268 y Fj(BZ_PARAM_ERROR)663
2371 y Fl(if)e Fj(f)h Fl(is)g Fj(NULL)663 2475 y Fl(or)g
Fj(blockSize100k)44 b(<)k(1)30 b Fl(or)g Fj(blockSize100k)44
b(>)k(9)572 2579 y(BZ_IO_ERROR)663 2683 y Fl(if)29 b
Fj(ferror(f))f Fl(is)h(nonzero)572 2786 y Fj(BZ_MEM_ERROR)663
2890 y Fl(if)g(insu16cien)m(t)g(memory)h(is)f(a)m(v)-5
b(ailable)572 2994 y Fj(BZ_OK)663 3098 y Fl(otherwise)150
3255 y(P)m(ossible)29 b(return)h(v)-5 b(alues:)572 3406
y(P)m(oin)m(ter)31 b(to)g(an)f(abstract)h Fj(BZFILE)663
3509 y Fl(if)e Fj(bzerror)f Fl(is)i Fj(BZ_OK)572 3613
y(NULL)663 3717 y Fl(otherwise)150 3874 y(Allo)m(w)m(able)g(next)g
(actions:)572 4025 y Fj(bzWrite)663 4129 y Fl(if)f Fj(bzerror)f
Fl(is)i Fj(BZ_OK)663 4232 y Fl((y)m(ou)h(could)e(go)i(directly)e(to)j
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(p)s(oin)m(tless))572 4336 y Fj(bzWriteClose)663 4440
y Fl(otherwise)150 4689 y Ff(3.4.6)63 b Fe(bzWrite)533
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i(the)g(14le.)150 5189 y(P)m(ossible)h(assignmen)m(ts)h(to)h
Fj(bzerror)p Fl(:)572 5340 y Fj(BZ_PARAM_ERROR)p eop
%%Page: 25 26
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Fl(or)i Fj(len)46 b(<)i(0)572 470 y(BZ_SEQUENCE_ERROR)663
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Fj(bzWrite)d Fl(are)i(illegal.)150 2128 y(All)42 b(memory)h(asso)s
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b Fl(35)p eop
%%Trailer
end
userdict /end-hook known{end-hook}if
%%EOF