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#include <stdlib.h>
#include <string.h>
#include "src/common.h"
static void uv_link_maybe_close(uv_link_t* link);
static void uv_link_def_alloc_cb(uv_link_t* link,
size_t suggested_size,
uv_buf_t* buf) {
buf->base = malloc(suggested_size);
buf->len = suggested_size;
CHECK_NE(buf->base, NULL, "uv_link_t: alloc_cb failure");
}
static void uv_link_def_read_cb(uv_link_t* link,
ssize_t nread,
const uv_buf_t* buf) {
if (buf != NULL)
free(buf->base);
}
int uv_link_init(uv_link_t* link, uv_link_methods_t const* methods) {
memset(link, 0, sizeof(*link));
link->alloc_cb = uv_link_def_alloc_cb;
link->read_cb = uv_link_def_read_cb;
link->methods = methods;
return 0;
}
#define CLOSE_WRAP(RES) \
do { \
int err; \
link->close_depth++; \
err = (RES); \
if (--link->close_depth == 0) \
uv_link_maybe_close(link); \
return err; \
} while (0)
int uv_link_propagate_write(uv_link_t* link, uv_link_t* source,
const uv_buf_t bufs[], unsigned int nbufs,
uv_stream_t* send_handle,
uv_link_write_cb cb, void* arg) {
if (link == NULL)
return UV_EFAULT;
CLOSE_WRAP(link->methods->write(link, source, bufs, nbufs, send_handle, cb,
arg));
}
int uv_link_propagate_shutdown(uv_link_t* link,
uv_link_t* source,
uv_link_shutdown_cb cb,
void* arg) {
if (link == NULL)
return UV_EFAULT;
CLOSE_WRAP(link->methods->shutdown(link, source, cb, arg));
}
int uv_link_read_start(uv_link_t* link) {
if (link == NULL)
return UV_EFAULT;
CLOSE_WRAP(link->methods->read_start(link));
}
int uv_link_read_stop(uv_link_t* link) {
if (link == NULL)
return UV_EFAULT;
CLOSE_WRAP(link->methods->read_stop(link));
}
int uv_link_try_write(uv_link_t* link,
const uv_buf_t bufs[],
unsigned int nbufs) {
if (link == NULL)
return UV_EFAULT;
CLOSE_WRAP(link->methods->try_write(link, bufs, nbufs));
}
void uv_link_close(uv_link_t* link, uv_link_close_cb cb) {
uv_link_propagate_close(link, link, cb);
}
static void uv_link_close_join(uv_link_t* link) {
if (--link->close_waiting == 0)
return link->saved_close_cb(link);
}
void uv_link_maybe_close(uv_link_t* link) {
uv_link_t* source;
if (link->pending_close_source == NULL)
return;
source = link->pending_close_source;
link->pending_close_source = NULL;
link->methods->close(link, source, uv_link_close_join);
}
void uv_link_propagate_close(uv_link_t* link, uv_link_t* source,
uv_link_close_cb cb) {
uv_link_t* root;
int count;
CHECK_EQ(link->child, NULL, "uv_link_t: attempt to close chained link");
/* Find root */
count = 1;
for (root = link; root->parent != NULL; root = root->parent)
count++;
/* NOTE: This is very important line. Only because we `+=` here the
* recursive propagation is possible
*/
source->close_waiting += count;
source->saved_close_cb = cb;
/* Go from the root to the leaf, disconnecting and closing everything */
while (root != NULL) {
uv_link_t* child;
child = root->child;
if (child != NULL)
CHECK_EQ(uv_link_unchain(root, child), 0, "close unchain");
if (root->close_depth == 0)
root->methods->close(root, source, uv_link_close_join);
else
root->pending_close_source = source;
root = child;
}
}
int uv_link_chain(uv_link_t* from, uv_link_t* to) {
if (from->child != NULL || to->parent != NULL)
return UV_EINVAL;
CHECK(to->methods->alloc_cb_override != NULL &&
to->methods->read_cb_override != NULL,
"Attempting to chain link without overriding callbacks");
from->child = to;
to->parent = from;
from->saved_alloc_cb = from->alloc_cb;
from->saved_read_cb = from->read_cb;
from->alloc_cb = to->methods->alloc_cb_override;
from->read_cb = to->methods->read_cb_override;
return 0;
}
int uv_link_unchain(uv_link_t* from, uv_link_t* to) {
if (from->child != to || to->parent != from)
return UV_EINVAL;
from->child = NULL;
to->parent = NULL;
from->alloc_cb = from->saved_alloc_cb;
from->read_cb = from->saved_read_cb;
from->saved_alloc_cb = NULL;
from->saved_read_cb = NULL;
return 0;
}
void uv_link_propagate_alloc_cb(uv_link_t* link,
size_t suggested_size,
uv_buf_t* buf) {
uv_link_t* target;
target = link;
if (link->child != NULL)
target = link->child;
target->close_depth++;
link->alloc_cb(target, suggested_size, buf);
if (--target->close_depth == 0)
uv_link_maybe_close(target);
}
void uv_link_propagate_read_cb(uv_link_t* link,
ssize_t nread,
const uv_buf_t* buf) {
uv_link_t* target;
target = link;
if (link->child != NULL)
target = link->child;
target->close_depth++;
link->read_cb(target, nread, buf);
if (--target->close_depth == 0)
uv_link_maybe_close(target);
}
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