Add compress and decompress examples

This commit is contained in:
Justine Tunney 2022-05-14 21:13:45 -07:00
parent 54e6f564c1
commit 6bf6f9e376
3 changed files with 204 additions and 3 deletions

92
examples/compress.c Normal file
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@ -0,0 +1,92 @@
#if 0
/*─────────────────────────────────────────────────────────────────╗
To the extent possible under law, Justine Tunney has waived
all copyright and related or neighboring rights to this file,
as it is written in the following disclaimers:
http://unlicense.org/ │
http://creativecommons.org/publicdomain/zero/1.0/ │
*/
#endif
#include "libc/assert.h"
#include "libc/errno.h"
#include "libc/log/check.h"
#include "libc/mem/mem.h"
#include "libc/runtime/gc.internal.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "third_party/zlib/zlib.h"
#define CHUNK 4096
// clang-format off
// make -j8 o//examples && dd if=/dev/urandom count=100 | tee a | o//examples/compress.com | o//examples/decompress.com >b && sha1sum a b
// clang-format on
int compressor(int infd, int outfd) {
z_stream zs;
int rc, flush;
unsigned have;
unsigned char *inbuf;
unsigned char *outbuf;
inbuf = gc(valloc(CHUNK));
outbuf = gc(valloc(CHUNK));
zs.zalloc = 0;
zs.zfree = 0;
zs.opaque = 0;
rc = deflateInit2(&zs, Z_DEFAULT_COMPRESSION, Z_DEFLATED, MAX_WBITS,
DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);
if (rc != Z_OK) return rc;
do {
rc = read(infd, inbuf, CHUNK);
if (rc == -1) {
deflateEnd(&zs);
return Z_ERRNO;
}
zs.avail_in = rc;
flush = !rc ? Z_FINISH : Z_SYNC_FLUSH;
zs.next_in = inbuf;
do {
zs.avail_out = CHUNK;
zs.next_out = outbuf;
rc = deflate(&zs, flush);
assert(rc != Z_STREAM_ERROR);
have = CHUNK - zs.avail_out;
if (write(outfd, outbuf, have) != have) {
deflateEnd(&zs);
return Z_ERRNO;
}
} while (!zs.avail_out);
assert(!zs.avail_in);
} while (flush != Z_FINISH);
assert(rc == Z_STREAM_END);
deflateEnd(&zs);
return Z_OK;
}
const char *zerr(int rc) {
switch (rc) {
case Z_ERRNO:
return strerror(errno);
case Z_STREAM_ERROR:
return "invalid compression level";
case Z_DATA_ERROR:
return "invalid or incomplete deflate data";
case Z_MEM_ERROR:
return "out of memory";
case Z_VERSION_ERROR:
return "zlib version mismatch!";
default:
unreachable;
}
}
int main(int argc, char *argv[]) {
int rc;
rc = compressor(0, 1);
if (rc == Z_OK) {
return 0;
} else {
fprintf(stderr, "error: compressor: %s\n", zerr(rc));
return 1;
}
}

100
examples/decompress.c Normal file
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@ -0,0 +1,100 @@
#if 0
/*─────────────────────────────────────────────────────────────────╗
To the extent possible under law, Justine Tunney has waived
all copyright and related or neighboring rights to this file,
as it is written in the following disclaimers:
http://unlicense.org/ │
http://creativecommons.org/publicdomain/zero/1.0/ │
*/
#endif
#include "libc/assert.h"
#include "libc/errno.h"
#include "libc/mem/mem.h"
#include "libc/runtime/gc.internal.h"
#include "libc/stdio/stdio.h"
#include "third_party/zlib/zlib.h"
#define CHUNK 4096
// clang-format off
// make -j8 o//examples && dd if=/dev/urandom count=100 | tee a | o//examples/compress.com | o//examples/decompress.com >b && sha1sum a b
// clang-format on
int decompressor(int infd, int outfd) {
int rc;
unsigned have;
z_stream zs;
unsigned char *inbuf;
unsigned char *outbuf;
inbuf = gc(valloc(CHUNK));
outbuf = gc(valloc(CHUNK));
zs.zalloc = Z_NULL;
zs.zfree = Z_NULL;
zs.opaque = Z_NULL;
zs.avail_in = 0;
zs.next_in = Z_NULL;
rc = inflateInit(&zs);
if (rc != Z_OK) return rc;
do {
rc = read(infd, inbuf, CHUNK);
if (rc == -1) {
inflateEnd(&zs);
return Z_ERRNO;
}
if (!rc) {
break;
}
zs.avail_in = rc;
zs.next_in = inbuf;
do {
zs.avail_out = CHUNK;
zs.next_out = outbuf;
rc = inflate(&zs, Z_SYNC_FLUSH);
assert(rc != Z_STREAM_ERROR);
switch (rc) {
case Z_NEED_DICT:
rc = Z_DATA_ERROR;
// fallthrough
case Z_DATA_ERROR:
case Z_MEM_ERROR:
inflateEnd(&zs);
return rc;
}
have = CHUNK - zs.avail_out;
if (write(outfd, outbuf, have) != have) {
inflateEnd(&zs);
return Z_ERRNO;
}
} while (!zs.avail_out);
} while (rc != Z_STREAM_END);
inflateEnd(&zs);
return rc == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
}
const char *zerr(int rc) {
switch (rc) {
case Z_ERRNO:
return strerror(errno);
case Z_STREAM_ERROR:
return "invalid compression level";
case Z_DATA_ERROR:
return "invalid or incomplete deflate data";
case Z_MEM_ERROR:
return "out of memory";
case Z_VERSION_ERROR:
return "zlib version mismatch!";
default:
unreachable;
}
}
int main(int argc, char *argv[]) {
int rc;
rc = decompressor(0, 1);
if (rc == Z_OK) {
return 0;
} else {
fprintf(stderr, "error: decompressor: %s\n", zerr(rc));
return 1;
}
}

View file

@ -21,6 +21,7 @@
#include "libc/calls/struct/sigset.h"
#include "libc/calls/struct/timespec.h"
#include "libc/calls/struct/timeval.h"
#include "libc/dce.h"
#include "libc/fmt/itoa.h"
#include "libc/intrin/kprintf.h"
#include "libc/log/check.h"
@ -34,6 +35,7 @@
#include "libc/sysv/consts/clone.h"
#include "libc/sysv/consts/ipproto.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/poll.h"
#include "libc/sysv/consts/prot.h"
#include "libc/sysv/consts/rlimit.h"
#include "libc/sysv/consts/sig.h"
@ -141,6 +143,14 @@ int Worker(void *id) {
char inbuf[1500], outbuf[512], *p, *q;
int clientip, client, inmsglen, outmsglen;
__atomic_load(&closingtime, &itsover, __ATOMIC_SEQ_CST);
if (itsover) break;
if (!IsLinux() &&
poll(&(struct pollfd){server, POLLIN}, 1, HEARTBEAT) < 1) {
continue;
}
// wait for client connection
clientaddrsize = sizeof(clientaddr);
client = accept(server, &clientaddr, &clientaddrsize);
@ -154,8 +164,6 @@ int Worker(void *id) {
// side-effect that the listening socket fails with EAGAIN, every
// several seconds. we can use that to our advantage to check for
// the ctrl-c shutdown event; otherwise, we retry the accept call
__atomic_load(&closingtime, &itsover, __ATOMIC_SEQ_CST);
if (itsover) break;
continue;
}
@ -274,7 +282,8 @@ int main(int argc, char *argv[]) {
__atomic_load(&workers, &haveleft, __ATOMIC_SEQ_CST);
if (!haveleft) break;
__builtin_ia32_pause();
if (usleep(HEARTBEAT * 1000) == -1 && closingtime) {
usleep(HEARTBEAT * 1000);
if (closingtime) {
kprintf("\rgreenbean is shutting down...\n");
}
}