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#include <u.h>
#include <base.h>
#include <zlib.h>
typedef struct buffer
{
union {
struct z_stream_s;
z_stream z;
};
ubyte buf[4098];
} buffer;
// -----------------------------------------------------------------------
// Reading
typedef struct flate·Reader
{
io·Reader rdr;
void* impl;
union {
struct buffer;
buffer b;
};
} flate·Reader;
flate·Reader*
flate·openreader(io·Reader rdr, void* r, mem·Allocator mem, void* m)
{
error err;
flate·Reader *zrdr;
zrdr = mem.alloc(m, 1, sizeof(*zrdr));
zrdr->zalloc = (void *(*)(void *, unsigned int, unsigned int))mem.alloc;
zrdr->zfree = mem.free;
zrdr->opaque = m;
zrdr->avail_in = rdr.read(r, 1, arrlen(zrdr->buf), zrdr->buf);
zrdr->next_in = zrdr->buf;
err = inflateInit(&zrdr->b.z);
switch (err) {
case Z_OK:
return zrdr;
case Z_MEM_ERROR:
errorf("zlib: not enough memory");
goto ERROR;
case Z_VERSION_ERROR:
errorf("zlib: incompatible version");
goto ERROR;
case Z_STREAM_ERROR:
errorf("zlib: incorrect input parameters");
goto ERROR;
default:
errorf("zlib: unrecognized error code");
}
ERROR:
errorf("zlib: msg: %s", zrdr->msg);
mem.free(m, zrdr);
return nil;
}
error
flate·closereader(flate·Reader *rdr)
{
int err;
flate·Reader zrdr;
zrdr = *rdr;
err = inflateEnd(&zrdr.b.z);
if (err != Z_OK) {
errorf("zlib: failed to cleanup");
return err;
}
rdr->zfree(rdr->opaque, rdr);
return 0;
}
int
flate·read(flate·Reader *rdr, int sz, int n, void *buf)
{
int r;
int err;
flate·Reader zrdr;
zrdr = *rdr;
zrdr.next_out = buf;
zrdr.avail_out = n*sz;
READ:
err = inflate(&zrdr.b.z, Z_STREAM_END);
switch (err) {
case Z_OK:
return n;
case Z_STREAM_END:
r = zrdr.next_out - (ubyte*)buf;
n -= r;
zrdr.avail_in = zrdr.rdr.read(zrdr.impl, 1, arrlen(zrdr.buf), zrdr.buf);
if (!zrdr.avail_in) {
return r;
}
zrdr.next_in = zrdr.buf;
goto READ;
case Z_NEED_DICT:
errorf("zlib: need input dictionary");
goto ERROR;
case Z_STREAM_ERROR:
errorf("zlib: inconsistent stream structure");
goto ERROR;
}
ERROR:
flate·closereader(rdr);
return -1;
}
// -----------------------------------------------------------------------
// Writing
struct flate·Writer
{
io·Writer wtr;
void* impl;
union {
struct buffer;
buffer b;
};
};
flate·Writer*
flate·openwriter(io·Writer wtr, void* w, mem·Allocator mem, void* m)
{
error err;
flate·Writer *zwtr;
zwtr = mem.alloc(m, 1, sizeof(*zwtr));
zwtr->zalloc = (void *(*)(void *, unsigned int, unsigned int))mem.alloc;
zwtr->zfree = mem.free;
zwtr->opaque = m;
zwtr->avail_in = 0;
err = deflateInit(&zwtr->b.z, Z_DEFAULT_COMPRESSION);
switch (err) {
case Z_OK:
return zwtr;
case Z_MEM_ERROR:
errorf("zlib: not enough memory");
goto ERROR;
case Z_VERSION_ERROR:
errorf("zlib: incompatible version");
goto ERROR;
case Z_STREAM_ERROR:
errorf("zlib: incorrect compression level");
goto ERROR;
default:
errorf("zlib: unrecognized error code");
}
ERROR:
errorf("zlib: msg: %s", zwtr->msg);
mem.free(m, zwtr);
return nil;
}
error
flate·closewriter(flate·Writer *wtr)
{
int err;
flate·Writer zwtr;
zwtr = *wtr;
err = deflateEnd(&zwtr.b.z);
if (err != Z_OK) {
errorf("zlib: failed to cleanup");
return err;
}
zwtr.zfree(zwtr.opaque, wtr);
return 0;
}
int
flate·write(flate·Writer *wtr, int sz, int n, void *buf)
{
int r;
int err;
flate·Writer zwtr;
zwtr = *wtr;
zwtr.next_out = buf;
DEFLATE:
zwtr.avail_out = n*sz;
err = deflate(&zwtr.z, Z_NO_FLUSH);
switch (err) {
case Z_STREAM_END:
return n;
case Z_OK:
r = (zwtr.next_out - (ubyte*)buf)/sz;
n -= r;
if (!n) {
return r;
}
buf += n;
goto DEFLATE;
case Z_STREAM_ERROR:
errorf("zlib: bad input");
goto ERROR;
case Z_BUF_ERROR:
if (!zwtr.avail_in) {
zwtr.avail_in += zwtr.wtr.write(zwtr.impl, 1, arrlen(zwtr.buf), buf);
if (!zwtr.avail_in) {
errorf("reader: failed read");
goto ERROR;
}
goto DEFLATE;
}
}
return 0;
ERROR:
errorf("zlib: %s", zwtr.msg);
return -1;
}
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