/* Handle stdout from CGI child. Duplicate of logic from the _read
* method of the real APR pipe bucket implementation. */
static apr_status_t aikido_read_stdout(apr_bucket *a, apr_file_t *out,
const char **str, apr_size_t *len)
{
char *buf;
apr_status_t rv;
*str = NULL;
*len = APR_BUCKET_BUFF_SIZE;
buf = apr_bucket_alloc(*len, a->list); /* XXX: check for failure? */
rv = apr_file_read(out, buf, len);
if (rv != APR_SUCCESS && rv != APR_EOF) {
apr_bucket_free(buf);
return rv;
}
if (*len > 0) {
struct aikido_bucket_data *data = a->data;
apr_bucket_heap *h;
/* Change the current bucket to refer to what we read */
a = apr_bucket_heap_make(a, buf, *len, apr_bucket_free);
h = a->data;
h->alloc_len = APR_BUCKET_BUFF_SIZE; /* note the real buffer size */
*str = buf;
APR_BUCKET_INSERT_AFTER(a, aikido_bucket_dup(data, a->list));
}
else {
apr_bucket_free(buf);
a = apr_bucket_immortal_make(a, "", 0);
*str = a->data;
}
return rv;
}
static apr_status_t pipe_bucket_read(apr_bucket *a, const char **str,
apr_size_t *len, apr_read_type_e block)
{
apr_file_t *p = a->data;
char *buf;
apr_status_t rv;
apr_interval_time_t timeout;
if (block == APR_NONBLOCK_READ) {
apr_file_pipe_timeout_get(p, &timeout);
apr_file_pipe_timeout_set(p, 0);
}
*str = NULL;
*len = APR_BUCKET_BUFF_SIZE;
buf = apr_bucket_alloc(*len, a->list); /* XXX: check for failure? */
rv = apr_file_read(p, buf, len);
if (block == APR_NONBLOCK_READ) {
apr_file_pipe_timeout_set(p, timeout);
}
if (rv != APR_SUCCESS && rv != APR_EOF) {
apr_bucket_free(buf);
return rv;
}
/*
* If there's more to read we have to keep the rest of the pipe
* for later. Otherwise, we'll close the pipe.
* XXX: Note that more complicated bucket types that
* refer to data not in memory and must therefore have a read()
* function similar to this one should be wary of copying this
* code because if they have a destroy function they probably
* want to migrate the bucket's subordinate structure from the
* old bucket to a raw new one and adjust it as appropriate,
* rather than destroying the old one and creating a completely
* new bucket.
*/
if (*len > 0) {
apr_bucket_heap *h;
/* Change the current bucket to refer to what we read */
a = apr_bucket_heap_make(a, buf, *len, apr_bucket_free);
h = a->data;
h->alloc_len = APR_BUCKET_BUFF_SIZE; /* note the real buffer size */
*str = buf;
APR_BUCKET_INSERT_AFTER(a, apr_bucket_pipe_create(p, a->list));
}
else {
apr_bucket_free(buf);
a = apr_bucket_immortal_make(a, "", 0);
*str = a->data;
if (rv == APR_EOF) {
apr_file_close(p);
}
}
return APR_SUCCESS;
}
APU_DECLARE(apr_bucket *) apr_bucket_immortal_create(const char *buf,
apr_size_t length,
apr_bucket_alloc_t *list)
{
apr_bucket *b = apr_bucket_alloc(sizeof(*b), list);
APR_BUCKET_INIT(b);
b->free = apr_bucket_free;
b->list = list;
return apr_bucket_immortal_make(b, buf, length);
}
static apr_status_t bucket_socket_ex_read(apr_bucket *a, const char **str,
apr_size_t *len,
apr_read_type_e block)
{
socket_ex_data *data = a->data;
apr_socket_t *p = data->sock;
char *buf;
apr_status_t rv;
apr_interval_time_t timeout;
if (block == APR_NONBLOCK_READ) {
apr_socket_timeout_get(p, &timeout);
apr_socket_timeout_set(p, 0);
}
*str = NULL;
*len = APR_BUCKET_BUFF_SIZE;
buf = apr_bucket_alloc(*len, a->list);
rv = apr_socket_recv(p, buf, len);
if (block == APR_NONBLOCK_READ) {
apr_socket_timeout_set(p, timeout);
}
if (rv != APR_SUCCESS && rv != APR_EOF) {
apr_bucket_free(buf);
return rv;
}
if (*len > 0) {
apr_bucket_heap *h;
/* count for stats */
*data->counter += *len;
/* Change the current bucket to refer to what we read */
a = apr_bucket_heap_make(a, buf, *len, apr_bucket_free);
h = a->data;
h->alloc_len = APR_BUCKET_BUFF_SIZE; /* note the real buffer size */
*str = buf;
APR_BUCKET_INSERT_AFTER(a, bucket_socket_ex_create(data, a->list));
}
else {
apr_bucket_free(buf);
a = apr_bucket_immortal_make(a, "", 0);
*str = a->data;
}
return APR_SUCCESS;
}
static apr_status_t
bucket_read(apr_bucket *bucket, const char **str, apr_size_t *len, apr_read_type_e block) {
char *buf;
ssize_t ret;
BucketData *data;
data = (BucketData *) bucket->data;
*str = NULL;
*len = 0;
if (!data->bufferResponse && block == APR_NONBLOCK_READ) {
/*
* The bucket brigade that Hooks::handleRequest() passes using
* ap_pass_brigade() is always passed through ap_content_length_filter,
* which is a filter which attempts to read all data from the
* bucket brigade and computes the Content-Length header from
* that. We don't want this to happen; because suppose that the
* Rails application sends back 1 GB of data, then
* ap_content_length_filter will buffer this entire 1 GB of data
* in memory before passing it to the HTTP client.
*
* ap_content_length_filter aborts and passes the bucket brigade
* down the filter chain when it encounters an APR_EAGAIN, except
* for the first read. So by returning APR_EAGAIN on every
* non-blocking read request, we can prevent ap_content_length_filter
* from buffering all data.
*/
//return APR_EAGAIN;
}
buf = (char *) apr_bucket_alloc(APR_BUCKET_BUFF_SIZE, bucket->list);
if (buf == NULL) {
return APR_ENOMEM;
}
do {
ret = read(data->state->connection, buf, APR_BUCKET_BUFF_SIZE);
} while (ret == -1 && errno == EINTR);
if (ret > 0) {
apr_bucket_heap *h;
data->state->bytesRead += ret;
*str = buf;
*len = ret;
bucket->data = NULL;
/* Change the current bucket (which is a Passenger Bucket) into a heap bucket
* that contains the data that we just read. This newly created heap bucket
* will be the first in the bucket list.
*/
bucket = apr_bucket_heap_make(bucket, buf, *len, apr_bucket_free);
h = (apr_bucket_heap *) bucket->data;
h->alloc_len = APR_BUCKET_BUFF_SIZE; /* note the real buffer size */
/* And after this newly created bucket we insert a new Passenger Bucket
* which can read the next chunk from the stream.
*/
APR_BUCKET_INSERT_AFTER(bucket, passenger_bucket_create(
data->state, bucket->list, data->bufferResponse));
/* The newly created Passenger Bucket has a reference to the session
* object, so we can delete data here.
*/
delete data;
return APR_SUCCESS;
} else if (ret == 0) {
data->state->completed = true;
delete data;
bucket->data = NULL;
apr_bucket_free(buf);
bucket = apr_bucket_immortal_make(bucket, "", 0);
*str = (const char *) bucket->data;
*len = 0;
return APR_SUCCESS;
} else /* ret == -1 */ {
int e = errno;
data->state->completed = true;
data->state->errorCode = e;
delete data;
bucket->data = NULL;
apr_bucket_free(buf);
return APR_FROM_OS_ERROR(e);
}
}
//本函数只处理一次buf读取操作，loop在caller中执行
static apr_status_t socket_bucket_read(apr_bucket *a, const char **str,
apr_size_t *len, apr_read_type_e block)
{
//把数据从a->data中读入到a->list中的node空间中
apr_socket_t *p = a->data;
char *buf;
apr_status_t rv;
apr_interval_time_t timeout;
if (block == APR_NONBLOCK_READ) {
apr_socket_timeout_get(p, &timeout);
apr_socket_timeout_set(p, 0);
}
*str = NULL;
*len = APR_BUCKET_BUFF_SIZE;
buf = apr_bucket_alloc(*len, a->list); /* XXX: check for failure? */
rv = apr_socket_recv(p, buf, len);
if (block == APR_NONBLOCK_READ) {
apr_socket_timeout_set(p, timeout);
}
if (rv != APR_SUCCESS && rv != APR_EOF) {
apr_bucket_free(buf);
return rv;
}
/*
* If there's more to read we have to keep the rest of the socket
* for later. XXX: Note that more complicated bucket types that
* refer to data not in memory and must therefore have a read()
* function similar to this one should be wary of copying this
* code because if they have a destroy function they probably
* want to migrate the bucket's subordinate structure from the
* old bucket to a raw new one and adjust it as appropriate,
* rather than destroying the old one and creating a completely
* new bucket.
* 如果read后还有剩余，则需要保留socket剩余部分下次再读。
* 类似这样的需要一个read()操作的非内存bucket，请谨慎copy当前代码，
* 原因见上面解释
*
*
* Even if there is nothing more to read, don't close the socket here
* as we have to use it to send any response :) We could shut it
* down for reading, but there is no benefit to doing so.
* read完成后不需要close/shut down socket
*
*
*/
if (*len > 0) {
apr_bucket_heap *h;
/* Change the current bucket to refer to what we read */
//把当前读取的那部分数据组织成一个heap bucket,并返回起始地址
a = apr_bucket_heap_make(a, buf, *len, apr_bucket_free);
h = a->data;
h->alloc_len = APR_BUCKET_BUFF_SIZE; /* note the real buffer size */
*str = buf;
//剩下的p作为一个新的socket bucket
APR_BUCKET_INSERT_AFTER(a, apr_bucket_socket_create(p, a->list));
}
else {
apr_bucket_free(buf);
a = apr_bucket_immortal_make(a, "", 0);
*str = a->data;
}
return APR_SUCCESS;
}
