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author | Petri Lehtinen <petri@digip.org> | 2018-02-09 10:10:34 +0200 |
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committer | GitHub <noreply@github.com> | 2018-02-09 10:10:34 +0200 |
commit | 03620980cfdf824ca5fe4ead256fdb2f242f8363 (patch) | |
tree | f9bc84c8488ce1906960e588ecfa746084b47066 /doc | |
parent | 248d62111c7b13d9076edf6f7881acaf32a7b4c3 (diff) | |
parent | a6138a07b6f302567254c1f51193d9017dcb8d3e (diff) | |
download | jansson-03620980cfdf824ca5fe4ead256fdb2f242f8363.zip jansson-03620980cfdf824ca5fe4ead256fdb2f242f8363.tar.gz jansson-03620980cfdf824ca5fe4ead256fdb2f242f8363.tar.bz2 |
Merge pull request #395 from akheron/doc-utf-8
Document encoding requirements for callbacks
Diffstat (limited to 'doc')
-rw-r--r-- | doc/apiref.rst | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/doc/apiref.rst b/doc/apiref.rst index f1a7e16..3945c11 100644 --- a/doc/apiref.rst +++ b/doc/apiref.rst @@ -1138,6 +1138,10 @@ These functions output UTF-8: the length of the buffer, and *data* is the corresponding :func:`json_dump_callback()` argument passed through. + *buffer* is guaranteed to be a valid UTF-8 string (i.e. multi-byte + code unit sequences are preserved). *buffer* never contains + embedded null bytes. + On error, the function should return -1 to stop the encoding process. On success, it should return 0. @@ -1333,11 +1337,19 @@ If no error or position information is needed, you can pass *NULL*. *buffer* points to a buffer of *buflen* bytes, and *data* is the corresponding :func:`json_load_callback()` argument passed through. - On success, the function should return the number of bytes read; a - returned value of 0 indicates that no data was read and that the - end of file has been reached. On error, the function should return + On success, the function should write at most *buflen* bytes to + *buffer*, and return the number of bytes written; a returned value + of 0 indicates that no data was produced and that the end of file + has been reached. On error, the function should return ``(size_t)-1`` to abort the decoding process. + In UTF-8, some code points are encoded as multi-byte sequences. The + callback function doesn't need to worry about this, as Jansson + handles it at a higher level. For example, you can safely read a + fixed number of bytes from a network connection without having to + care about code unit sequences broken apart by the chunk + boundaries. + .. versionadded:: 2.4 .. function:: json_t *json_load_callback(json_load_callback_t callback, void *data, size_t flags, json_error_t *error) |