1iob_write(3) Library Functions Manual iob_write(3)
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6 iob_write - send I/O batch through callback
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9 #include <iob.h>
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11 typedef int64 (*io_write_callback)(int64 s,const void* buf,uint64 n);
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13 int64 iob_write(int64 s,io_batch* b,io_write_callback cb);
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16 iob_write sends the (rest of) b through the callback cb, passing s as
17 first argument. cb is expected to behave like io_trywrite(2).
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19 This interface is intended to send an I/O batch through a filter, for
20 example to encrypt or compress it. If you just want to send an I/O
21 batch to a socket, use iob_send instead.
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23 iob_write returns the number of bytes written, 0 if there were no more
24 bytes to be written in the batch, -1 for EAGAIN, or -3 for a permanent
25 error (for example "connection reset by peer").
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27 The normal usage pattern is using io_wait to know when a descriptor is
28 writable, and then calling iob_write until it returns 0, -1 or -3.
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30 If it returns 0, terminate the loop (everything was written OK). If it
31 returns -1, call io_wait again. If it returned -3, signal an error.
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35 iob_write will continue to call your callback until it returns an
36 error. So if you are in a state machine, for example a web server
37 using this for SSL support, make sure to write at most n bytes at a
38 time (e.g. 64k) and the next time you are called return -1. Otherwise
39 iob_write might not return until the whole file is served.
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43 iob_send(3)
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47 iob_write(3)