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iolayer.c
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iolayer.c
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#include "io.h"
#include "iolayer.h"
#include "log.h"
#include <stdlib.h>
#include <stdio.h>
#ifdef _MSC_VER
#include <io.h>
#endif
#define IOL_DEB(x)
char *io_type_names[] = { "FDSEEK", "FDNOSEEK", "BUFFER", "CBSEEK", "CBNOSEEK", "BUFCHAIN" };
/*
=head1 NAME
iolayer.c - encapsulates different source of data into a single framework.
=head1 SYNOPSIS
io_glue *ig = io_new_fd( fileno(stdin) );
method = io_reqmeth( IOL_NOSEEK | IOL_MMAP ); // not implemented yet
io_glue_commit_types(ig); // always assume IOL_SEEK for now
switch (method) {
case IOL_NOSEEK:
code that uses ig->readcb()
to read data goes here.
break;
case IOL_MMAP:
code that uses ig->readcb()
to read data goes here.
break;
}
io_glue_DESTROY(ig);
// and much more
=head1 DESCRIPTION
iolayer.c implements the basic functions to create and destroy io_glue
objects for Imager. The typical usage pattern for data sources is:
1. Create the source (io_new_fd)
2. Define how you want to get data from it (io_reqmeth)
3. read from it using the interface requested (ig->readdb, ig->mmapcb)
4. Close the source, which
shouldn't really close the underlying source. (io_glue DESTROY)
=head1 FUNCTION REFERENCE
Some of these functions are internal.
=over
=cut
*/
static ssize_t fd_read(io_glue *ig, void *buf, size_t count);
static ssize_t fd_write(io_glue *ig, const void *buf, size_t count);
static off_t fd_seek(io_glue *ig, off_t offset, int whence);
static void fd_close(io_glue *ig);
static ssize_t fd_size(io_glue *ig);
/*
* Callbacks for sources that cannot seek
*/
/* fakeseek_read: read method for when emulating a seekable source
static
ssize_t
fakeseek_read(io_glue *ig, void *buf, size_t count) {
io_ex_fseek *exdata = ig->exdata;
return 0;
}
*/
/*
* Callbacks for sources that can seek
*/
/*
=item realseek_read(ig, buf, count)
Does the reading from a source that can be seeked on
ig - io_glue object
buf - buffer to return data in
count - number of bytes to read into buffer max
=cut
*/
static
ssize_t
realseek_read(io_glue *ig, void *buf, size_t count) {
io_ex_rseek *ier = ig->exdata;
void *p = ig->source.cb.p;
ssize_t rc = 0;
size_t bc = 0;
char *cbuf = buf;
IOL_DEB( printf("realseek_read: fd = %d, ier->cpos = %ld, buf = %p, "
"count = %d\n", fd, (long) ier->cpos, buf, count) );
/* Is this a good idea? Would it be better to handle differently?
skip handling? */
while( count!=bc && (rc = ig->source.cb.readcb(p,cbuf+bc,count-bc))>0 ) {
bc+=rc;
}
ier->cpos += bc;
IOL_DEB( printf("realseek_read: rc = %d, bc = %d\n", rc, bc) );
return bc;
}
/*
=item realseek_write(ig, buf, count)
Does the writing to a 'source' that can be seeked on
ig - io_glue object
buf - buffer that contains data
count - number of bytes to write
=cut
*/
static
ssize_t
realseek_write(io_glue *ig, const void *buf, size_t count) {
io_ex_rseek *ier = ig->exdata;
void *p = ig->source.cb.p;
ssize_t rc = 0;
size_t bc = 0;
char *cbuf = (char*)buf;
IOL_DEB( printf("realseek_write: ig = %p, ier->cpos = %ld, buf = %p, "
"count = %d\n", ig, (long) ier->cpos, buf, count) );
/* Is this a good idea? Would it be better to handle differently?
skip handling? */
while( count!=bc && (rc = ig->source.cb.writecb(p,cbuf+bc,count-bc))>0 ) {
bc+=rc;
}
ier->cpos += bc;
IOL_DEB( printf("realseek_write: rc = %d, bc = %d\n", rc, bc) );
return bc;
}
/*
=item realseek_close(ig)
Closes a source that can be seeked on. Not sure if this should be an
actual close or not. Does nothing for now. Should be fixed.
ig - data source
=cut */
static
void
realseek_close(io_glue *ig) {
mm_log((1, "realseek_close(ig %p)\n", ig));
if (ig->source.cb.closecb)
ig->source.cb.closecb(ig->source.cb.p);
}
/* realseek_seek(ig, offset, whence)
Implements seeking for a source that is seekable, the purpose of having this is to be able to
have an offset into a file that is different from what the underlying library thinks.
ig - data source
offset - offset into stream
whence - whence argument a la lseek
=cut
*/
static
off_t
realseek_seek(io_glue *ig, off_t offset, int whence) {
/* io_ex_rseek *ier = ig->exdata; Needed later */
void *p = ig->source.cb.p;
int rc;
IOL_DEB( printf("realseek_seek(ig %p, offset %ld, whence %d)\n", ig, (long) offset, whence) );
rc = ig->source.cb.seekcb(p, offset, whence);
IOL_DEB( printf("realseek_seek: rc %ld\n", (long) rc) );
return rc;
/* FIXME: How about implementing this offset handling stuff? */
}
/*
* Callbacks for sources that are a fixed size buffer
*/
/*
=item buffer_read(ig, buf, count)
Does the reading from a buffer source
ig - io_glue object
buf - buffer to return data in
count - number of bytes to read into buffer max
=cut
*/
static
ssize_t
buffer_read(io_glue *ig, void *buf, size_t count) {
io_ex_buffer *ieb = ig->exdata;
char *cbuf = buf;
IOL_DEB( printf("buffer_read: fd = %d, ier->cpos = %ld, buf = %p, count = %d\n", fd, (long) ier->cpos, buf, count) );
if ( ieb->cpos+count > ig->source.buffer.len ) {
mm_log((1,"buffer_read: short read: cpos=%d, len=%d, count=%d\n", ieb->cpos, ig->source.buffer.len));
count = ig->source.buffer.len - ieb->cpos;
}
memcpy(buf, ig->source.buffer.data+ieb->cpos, count);
ieb->cpos += count;
IOL_DEB( printf("buffer_read: rc = %d, count = %d\n", rc, count) );
return count;
}
/*
=item buffer_write(ig, buf, count)
Does nothing, returns -1
ig - io_glue object
buf - buffer that contains data
count - number of bytes to write
=cut
*/
static
ssize_t
buffer_write(io_glue *ig, const void *buf, size_t count) {
mm_log((1, "buffer_write called, this method should never be called.\n"));
return -1;
}
/*
=item buffer_close(ig)
Closes a source that can be seeked on. Not sure if this should be an actual close
or not. Does nothing for now. Should be fixed.
ig - data source
=cut
*/
static
void
buffer_close(io_glue *ig) {
mm_log((1, "buffer_close(ig %p)\n", ig));
/* FIXME: Do stuff here */
}
/* buffer_seek(ig, offset, whence)
Implements seeking for a buffer source.
ig - data source
offset - offset into stream
whence - whence argument a la lseek
=cut
*/
static
off_t
buffer_seek(io_glue *ig, off_t offset, int whence) {
io_ex_buffer *ieb = ig->exdata;
off_t reqpos = offset
+ (whence == SEEK_CUR)*ieb->cpos
+ (whence == SEEK_END)*ig->source.buffer.len;
if (reqpos > ig->source.buffer.len) {
mm_log((1, "seeking out of readable range\n"));
return (off_t)-1;
}
ieb->cpos = reqpos;
IOL_DEB( printf("buffer_seek(ig %p, offset %ld, whence %d)\n", ig, (long) offset, whence) );
return reqpos;
/* FIXME: How about implementing this offset handling stuff? */
}
/*
* Callbacks for sources that are a chain of variable sized buffers
*/
/* Helper functions for buffer chains */
static
io_blink*
io_blink_new(void) {
io_blink *ib;
mm_log((1, "io_blink_new()\n"));
ib = mymalloc(sizeof(io_blink));
ib->next = NULL;
ib->prev = NULL;
ib->len = BBSIZ;
memset(&ib->buf, 0, ib->len);
return ib;
}
/*
=item io_bchain_advance(ieb)
Advances the buffer chain to the next link - extending if
necessary. Also adjusts the cpos and tfill counters as needed.
ieb - buffer chain object
=cut
*/
static
void
io_bchain_advance(io_ex_bchain *ieb) {
if (ieb->cp->next == NULL) {
ieb->tail = io_blink_new();
ieb->tail->prev = ieb->cp;
ieb->cp->next = ieb->tail;
ieb->tfill = 0; /* Only set this if we added a new slice */
}
ieb->cp = ieb->cp->next;
ieb->cpos = 0;
}
/*
=item io_bchain_destroy()
frees all resources used by a buffer chain.
=cut
*/
void
io_destroy_bufchain(io_ex_bchain *ieb) {
io_blink *cp;
mm_log((1, "io_destroy_bufchain(ieb %p)\n", ieb));
cp = ieb->head;
while(cp) {
io_blink *t = cp->next;
myfree(cp);
cp = t;
}
}
/*
static
void
bufchain_dump(io_ex_bchain *ieb) {
mm_log((1, " buf_chain_dump(ieb %p)\n"));
mm_log((1, " buf_chain_dump: ieb->offset = %d\n", ieb->offset));
mm_log((1, " buf_chain_dump: ieb->length = %d\n", ieb->length));
mm_log((1, " buf_chain_dump: ieb->head = %p\n", ieb->head ));
mm_log((1, " buf_chain_dump: ieb->tail = %p\n", ieb->tail ));
mm_log((1, " buf_chain_dump: ieb->tfill = %d\n", ieb->tfill ));
mm_log((1, " buf_chain_dump: ieb->cp = %p\n", ieb->cp ));
mm_log((1, " buf_chain_dump: ieb->cpos = %d\n", ieb->cpos ));
mm_log((1, " buf_chain_dump: ieb->gpos = %d\n", ieb->gpos ));
}
*/
/*
* TRUE if lengths are NOT equal
*/
/*
static
void
chainlencert( io_glue *ig ) {
int clen;
int cfl = 0;
size_t csize = 0;
size_t cpos = 0;
io_ex_bchain *ieb = ig->exdata;
io_blink *cp = ieb->head;
if (ieb->gpos > ieb->length) mm_log((1, "BBAR : ieb->gpos = %d, ieb->length = %d\n", ieb->gpos, ieb->length));
while(cp) {
clen = (cp == ieb->tail) ? ieb->tfill : cp->len;
if (ieb->head == cp && cp->prev) mm_log((1, "Head of chain has a non null prev\n"));
if (ieb->tail == cp && cp->next) mm_log((1, "Tail of chain has a non null next\n"));
if (ieb->head != cp && !cp->prev) mm_log((1, "Middle of chain has a null prev\n"));
if (ieb->tail != cp && !cp->next) mm_log((1, "Middle of chain has a null next\n"));
if (cp->prev && cp->prev->next != cp) mm_log((1, "%p = cp->prev->next != cp\n", cp->prev->next));
if (cp->next && cp->next->prev != cp) mm_log((1, "%p cp->next->prev != cp\n", cp->next->prev));
if (cp == ieb->cp) {
cfl = 1;
cpos += ieb->cpos;
}
if (!cfl) cpos += clen;
csize += clen;
cp = cp->next;
}
if (( csize != ieb->length )) mm_log((1, "BAR : csize = %d, ieb->length = %d\n", csize, ieb->length));
if (( cpos != ieb->gpos )) mm_log((1, "BAR : cpos = %d, ieb->gpos = %d\n", cpos, ieb->gpos ));
}
static
void
chaincert( io_glue *ig) {
size_t csize = 0;
io_ex_bchain *ieb = ig->exdata;
io_blink *cp = ieb->head;
mm_log((1, "Chain verification.\n"));
mm_log((1, " buf_chain_dump: ieb->offset = %d\n", ieb->offset));
mm_log((1, " buf_chain_dump: ieb->length = %d\n", ieb->length));
mm_log((1, " buf_chain_dump: ieb->head = %p\n", ieb->head ));
mm_log((1, " buf_chain_dump: ieb->tail = %p\n", ieb->tail ));
mm_log((1, " buf_chain_dump: ieb->tfill = %d\n", ieb->tfill ));
mm_log((1, " buf_chain_dump: ieb->cp = %p\n", ieb->cp ));
mm_log((1, " buf_chain_dump: ieb->cpos = %d\n", ieb->cpos ));
mm_log((1, " buf_chain_dump: ieb->gpos = %d\n", ieb->gpos ));
while(cp) {
int clen = cp == ieb->tail ? ieb->tfill : cp->len;
mm_log((1, "link: %p <- %p -> %p\n", cp->prev, cp, cp->next));
if (ieb->head == cp && cp->prev) mm_log((1, "Head of chain has a non null prev\n"));
if (ieb->tail == cp && cp->next) mm_log((1, "Tail of chain has a non null next\n"));
if (ieb->head != cp && !cp->prev) mm_log((1, "Middle of chain has a null prev\n"));
if (ieb->tail != cp && !cp->next) mm_log((1, "Middle of chain has a null next\n"));
if (cp->prev && cp->prev->next != cp) mm_log((1, "%p = cp->prev->next != cp\n", cp->prev->next));
if (cp->next && cp->next->prev != cp) mm_log((1, "%p cp->next->prev != cp\n", cp->next->prev));
csize += clen;
cp = cp->next;
}
mm_log((1, "csize = %d %s ieb->length = %d\n", csize, csize == ieb->length ? "==" : "!=", ieb->length));
}
*/
/*
=item bufchain_read(ig, buf, count)
Does the reading from a source that can be seeked on
ig - io_glue object
buf - buffer to return data in
count - number of bytes to read into buffer max
=cut
*/
static
ssize_t
bufchain_read(io_glue *ig, void *buf, size_t count) {
io_ex_bchain *ieb = ig->exdata;
size_t scount = count;
char *cbuf = buf;
size_t sk;
mm_log((1, "bufchain_read(ig %p, buf %p, count %ld)\n", ig, buf, count));
while( scount ) {
int clen = (ieb->cp == ieb->tail) ? ieb->tfill : ieb->cp->len;
if (clen == ieb->cpos) {
if (ieb->cp == ieb->tail) break; /* EOF */
ieb->cp = ieb->cp->next;
ieb->cpos = 0;
clen = (ieb->cp == ieb->tail) ? ieb->tfill : ieb->cp->len;
}
sk = clen - ieb->cpos;
sk = sk > scount ? scount : sk;
memcpy(&cbuf[count-scount], &ieb->cp->buf[ieb->cpos], sk);
scount -= sk;
ieb->cpos += sk;
ieb->gpos += sk;
}
mm_log((1, "bufchain_read: returning %d\n", count-scount));
return count-scount;
}
/*
=item bufchain_write(ig, buf, count)
Does the writing to a 'source' that can be seeked on
ig - io_glue object
buf - buffer that contains data
count - number of bytes to write
=cut
*/
static
ssize_t
bufchain_write(io_glue *ig, const void *buf, size_t count) {
char *cbuf = (char *)buf;
io_ex_bchain *ieb = ig->exdata;
size_t ocount = count;
size_t sk;
mm_log((1, "bufchain_write: ig = %p, buf = %p, count = %d\n", ig, buf, count));
IOL_DEB( printf("bufchain_write: ig = %p, ieb->cpos = %ld, buf = %p, count = %d\n", ig, (long) ieb->cpos, buf, count) );
while(count) {
mm_log((2, "bufchain_write: - looping - count = %d\n", count));
if (ieb->cp->len == ieb->cpos) {
mm_log((1, "bufchain_write: cp->len == ieb->cpos = %d - advancing chain\n", (long) ieb->cpos));
io_bchain_advance(ieb);
}
sk = ieb->cp->len - ieb->cpos;
sk = sk > count ? count : sk;
memcpy(&ieb->cp->buf[ieb->cpos], &cbuf[ocount-count], sk);
if (ieb->cp == ieb->tail) {
int extend = ieb->cpos + sk - ieb->tfill;
mm_log((2, "bufchain_write: extending tail by %d\n", extend));
if (extend > 0) {
ieb->length += extend;
ieb->tfill += extend;
}
}
ieb->cpos += sk;
ieb->gpos += sk;
count -= sk;
}
return ocount;
}
/*
=item bufchain_close(ig)
Closes a source that can be seeked on. Not sure if this should be an actual close
or not. Does nothing for now. Should be fixed.
ig - data source
=cut
*/
static
void
bufchain_close(io_glue *ig) {
mm_log((1, "bufchain_close(ig %p)\n",ig));
IOL_DEB( printf("bufchain_close(ig %p)\n", ig) );
/* FIXME: Commit a seek point here */
}
/* bufchain_seek(ig, offset, whence)
Implements seeking for a source that is seekable, the purpose of having this is to be able to
have an offset into a file that is different from what the underlying library thinks.
ig - data source
offset - offset into stream
whence - whence argument a la lseek
=cut
*/
static
off_t
bufchain_seek(io_glue *ig, off_t offset, int whence) {
io_ex_bchain *ieb = ig->exdata;
io_blink *ib = NULL;
int wrlen;
off_t cof = 0;
off_t scount = offset;
off_t sk;
mm_log((1, "bufchain_seek(ig %p, offset %ld, whence %d)\n", ig, offset, whence));
switch (whence) {
case SEEK_SET: /* SEEK_SET = 0, From the top */
ieb->cp = ieb->head;
ieb->cpos = 0;
ieb->gpos = 0;
while( scount ) {
int clen = (ieb->cp == ieb->tail) ? ieb->tfill : ieb->cp->len;
if (clen == ieb->cpos) {
if (ieb->cp == ieb->tail) break; /* EOF */
ieb->cp = ieb->cp->next;
ieb->cpos = 0;
clen = (ieb->cp == ieb->tail) ? ieb->tfill : ieb->cp->len;
}
sk = clen - ieb->cpos;
sk = sk > scount ? scount : sk;
scount -= sk;
ieb->cpos += sk;
ieb->gpos += sk;
}
wrlen = scount;
if (wrlen > 0) {
/*
* extending file - get ieb into consistent state and then
* call write which will get it to the correct position
*/
char TB[BBSIZ];
memset(TB, 0, BBSIZ);
ieb->gpos = ieb->length;
ieb->cpos = ieb->tfill;
while(wrlen > 0) {
ssize_t rc, wl = i_min(wrlen, BBSIZ);
mm_log((1, "bufchain_seek: wrlen = %d, wl = %d\n", wrlen, wl));
rc = bufchain_write( ig, TB, wl );
if (rc != wl) m_fatal(0, "bufchain_seek: Unable to extend file\n");
wrlen -= rc;
}
}
break;
case SEEK_CUR:
m_fatal(123, "SEEK_CUR IS NOT IMPLEMENTED\n");
/*
case SEEK_CUR:
ib = ieb->cp;
if (cof < 0) {
cof += ib->cpos;
cpos = 0;
while(cof < 0 && ib->prev) {
ib = ib->prev;
cof += ib->len;
}
*/
case SEEK_END: /* SEEK_END = 2 */
if (cof>0) m_fatal(0, "bufchain_seek: SEEK_END + %d : Extending files via seek not supported!\n", cof);
ieb->cp = ieb->tail;
ieb->cpos = ieb->tfill;
if (cof<0) {
cof += ieb->cpos;
ieb->cpos = 0;
while(cof<0 && ib->prev) {
ib = ib->prev;
cof += ib->len;
}
if (cof<0) m_fatal(0, "bufchain_seek: Tried to seek before start of file\n");
ieb->gpos = ieb->length+offset;
ieb->cpos = cof;
}
break;
default:
m_fatal(0, "bufchain_seek: Unhandled seek request: whence = %d\n", whence );
}
mm_log((2, "bufchain_seek: returning ieb->gpos = %d\n", ieb->gpos));
return ieb->gpos;
}
/*
* Methods for setting up data source
*/
/*
=item io_obj_setp_buffer(io, p, len)
Sets an io_object for reading from a buffer source
io - io object that describes a source
p - pointer to buffer
len - length of buffer
=cut
*/
void
io_obj_setp_buffer(io_obj *io, char *p, size_t len, closebufp closecb, void *closedata) {
io->buffer.type = BUFFER;
io->buffer.data = p;
io->buffer.len = len;
io->buffer.closecb = closecb;
io->buffer.closedata = closedata;
}
/*
=item io_obj_setp_buchain(io)
Sets an io_object for reading/writing from a buffer source
io - io object that describes a source
p - pointer to buffer
len - length of buffer
=cut
*/
void
io_obj_setp_bufchain(io_obj *io) {
io->type = BUFCHAIN;
}
/*
=item io_obj_setp_cb2(io, p, readcb, writecb, seekcb, closecb, destroycb)
Sets an io_object for reading from a source that uses callbacks
io - io object that describes a source
p - pointer to data for callbacks
readcb - read callback to read from source
writecb - write callback to write to source
seekcb - seek callback to seek on source
closecb - flush any pending data
destroycb - release any extra resources
=cut
*/
void
io_obj_setp_cb2(io_obj *io, void *p, readl readcb, writel writecb, seekl seekcb, closel closecb, destroyl destroycb) {
io->cb.type = CBSEEK;
io->cb.p = p;
io->cb.readcb = readcb;
io->cb.writecb = writecb;
io->cb.seekcb = seekcb;
io->cb.closecb = closecb;
io->cb.destroycb = destroycb;
}
void
io_obj_setp_cb(io_obj *io, void *p, readl readcb, writel writecb,
seekl seekcb) {
io_obj_setp_cb2(io, p, readcb, writecb, seekcb, NULL, NULL);
}
/*
=item io_glue_commit_types(ig)
Creates buffers and initializes structures to read with the chosen interface.
ig - io_glue object
=cut
*/
void
io_glue_commit_types(io_glue *ig) {
io_type inn = ig->source.type;
mm_log((1, "io_glue_commit_types(ig %p)\n", ig));
mm_log((1, "io_glue_commit_types: source type %d (%s)\n", inn, io_type_names[inn]));
if (ig->flags & 0x01) {
mm_log((1, "io_glue_commit_types: type already set up\n"));
return;
}
switch (inn) {
case BUFCHAIN:
{
io_ex_bchain *ieb = mymalloc(sizeof(io_ex_bchain));
ieb->offset = 0;
ieb->length = 0;
ieb->cpos = 0;
ieb->gpos = 0;
ieb->tfill = 0;
ieb->head = io_blink_new();
ieb->cp = ieb->head;
ieb->tail = ieb->head;
ig->exdata = ieb;
ig->readcb = bufchain_read;
ig->writecb = bufchain_write;
ig->seekcb = bufchain_seek;
ig->closecb = bufchain_close;
}
break;
case CBSEEK:
{
io_ex_rseek *ier = mymalloc(sizeof(io_ex_rseek));
ier->offset = 0;
ier->cpos = 0;
ig->exdata = ier;
ig->readcb = realseek_read;
ig->writecb = realseek_write;
ig->seekcb = realseek_seek;
ig->closecb = realseek_close;
}
break;
case BUFFER:
{
io_ex_buffer *ieb = mymalloc(sizeof(io_ex_buffer));
ieb->offset = 0;
ieb->cpos = 0;
ig->exdata = ieb;
ig->readcb = buffer_read;
ig->writecb = buffer_write;
ig->seekcb = buffer_seek;
ig->closecb = buffer_close;
}
break;
case FDSEEK:
{
ig->exdata = NULL;
ig->readcb = fd_read;
ig->writecb = fd_write;
ig->seekcb = fd_seek;
ig->closecb = fd_close;
break;
}
}
ig->flags |= 0x01; /* indicate source has been setup already */
}
/*
=item io_glue_gettypes(ig, reqmeth)
Returns a set of compatible interfaces to read data with.
ig - io_glue object
reqmeth - request mask
The request mask is a bit mask (of something that hasn't been implemented yet)
of interfaces that it would like to read data from the source which the ig
describes.
=cut
*/
void
io_glue_gettypes(io_glue *ig, int reqmeth) {
ig = NULL;
reqmeth = 0;
/* FIXME: Implement this function! */
/* if (ig->source.type =
if (reqmeth & IO_BUFF) */
}
/*
=item io_new_bufchain()
returns a new io_glue object that has the 'empty' source and but can
be written to and read from later (like a pseudo file).
=cut
*/
io_glue *
io_new_bufchain() {
io_glue *ig;
mm_log((1, "io_new_bufchain()\n"));
ig = mymalloc(sizeof(io_glue));
memset(ig, 0, sizeof(*ig));
io_obj_setp_bufchain(&ig->source);
return ig;
}
/*
=item io_new_buffer(data, len)
Returns a new io_glue object that has the source defined as reading
from specified buffer. Note that the buffer is not copied.
data - buffer to read from
len - length of buffer
=cut
*/
io_glue *
io_new_buffer(char *data, size_t len, closebufp closecb, void *closedata) {
io_glue *ig;
mm_log((1, "io_new_buffer(data %p, len %d, closecb %p, closedata %p)\n", data, len, closecb, closedata));
ig = mymalloc(sizeof(io_glue));
memset(ig, 0, sizeof(*ig));
io_obj_setp_buffer(&ig->source, data, len, closecb, closedata);
ig->flags = 0;
return ig;
}
/*
=item io_new_fd(fd)
returns a new io_glue object that has the source defined as reading
from specified filedescriptor. Note that the the interface to recieving
data from the io_glue callbacks hasn't been done yet.
fd - file descriptor to read/write from
=cut
*/
io_glue *
io_new_fd(int fd) {
io_glue *ig;
mm_log((1, "io_new_fd(fd %d)\n", fd));
ig = mymalloc(sizeof(io_glue));
memset(ig, 0, sizeof(*ig));
ig->source.type = FDSEEK;
ig->source.fdseek.fd = fd;
ig->flags = 0;
#if 0
#ifdef _MSC_VER
io_obj_setp_cb(&ig->source, (void*)fd, _read, _write, _lseek);
#else
io_obj_setp_cb(&ig->source, (void*)fd, read, write, lseek);
#endif
#endif