Re: [PATCH 1/3] ios: Introduce ios_flush and ios_dev_<...>_flush.

[Jose E. Marchesi]

Hi Ege!

    Those functions are currently ineffective. This is a preparation patch
    for stream IO implementation.

OK for master.
Thanks.
    
    2020-07-11  Egeyar Bagcioglu  <egeyar@gmail.com>
    
            * libpoke/ios.h (ios_flush): New.
            * libpoke/ios.c (ios_flush): New.
            * libpoke/ios-dev.h (struct ios_dev_if): Add new member "flush".
            * libpoke/ios-dev-file.c (ios_dev_file_flush): New.
            * libpoke/ios-dev-mem.c (ios_dev_mem_flush): New.
            * libpoke/ios-dev-nbd.c (ios_dev_nbd_flush): New.
    ---
     libpoke/ios-dev-file.c | 7 +++++++
     libpoke/ios-dev-mem.c  | 7 +++++++
     libpoke/ios-dev-nbd.c  | 7 +++++++
     libpoke/ios-dev.h      | 5 +++++
     libpoke/ios.c          | 6 ++++++
     libpoke/ios.h          | 8 ++++++++
     6 files changed, 40 insertions(+)
    
    diff --git a/libpoke/ios-dev-file.c b/libpoke/ios-dev-file.c
    index fb42ed4f..4e4f3e63 100644
    --- a/libpoke/ios-dev-file.c
    +++ b/libpoke/ios-dev-file.c
    @@ -203,6 +203,12 @@ ios_dev_file_size (void *iod)
       return st.st_size;
     }
     
    +static int
    +ios_dev_file_flush (void *iod, ios_dev_off offset)
    +{
    +  return IOS_OK;
    +}
    +
     struct ios_dev_if ios_dev_file
       __attribute__ ((visibility ("hidden"))) =
       {
    @@ -213,4 +219,5 @@ struct ios_dev_if ios_dev_file
        .pwrite = ios_dev_file_pwrite,
        .get_flags = ios_dev_file_get_flags,
        .size = ios_dev_file_size,
    +   .flush = ios_dev_file_flush
       };
    diff --git a/libpoke/ios-dev-mem.c b/libpoke/ios-dev-mem.c
    index fba99d41..56c3d42b 100644
    --- a/libpoke/ios-dev-mem.c
    +++ b/libpoke/ios-dev-mem.c
    @@ -131,6 +131,12 @@ ios_dev_mem_size (void *iod)
       return mio->size;
     }
     
    +static int
    +ios_dev_mem_flush (void *iod, ios_dev_off offset)
    +{
    +  return IOS_OK;
    +}
    +
     struct ios_dev_if ios_dev_mem
       __attribute__ ((visibility ("hidden"))) =
       {
    @@ -141,4 +147,5 @@ struct ios_dev_if ios_dev_mem
        .pwrite = ios_dev_mem_pwrite,
        .get_flags = ios_dev_mem_get_flags,
        .size = ios_dev_mem_size,
    +   .flush = ios_dev_mem_flush,
       };
    diff --git a/libpoke/ios-dev-nbd.c b/libpoke/ios-dev-nbd.c
    index cfc68d48..9ed1834e 100644
    --- a/libpoke/ios-dev-nbd.c
    +++ b/libpoke/ios-dev-nbd.c
    @@ -169,6 +169,12 @@ ios_dev_nbd_size (void *iod)
       return nio->size;
     }
     
    +static int
    +ios_dev_nbd_flush (void *iod, ios_dev_off offset)
    +{
    +  return IOS_OK;
    +}
    +
     struct ios_dev_if ios_dev_nbd
       __attribute__ ((visibility ("hidden"))) =
       {
    @@ -179,4 +185,5 @@ struct ios_dev_if ios_dev_nbd
        .pwrite = ios_dev_nbd_pwrite,
        .get_flags = ios_dev_nbd_get_flags,
        .size = ios_dev_nbd_size,
    +   .flush = ios_dev_nbd_flush,
       };
    diff --git a/libpoke/ios-dev.h b/libpoke/ios-dev.h
    index fa5f6a06..8461bb35 100644
    --- a/libpoke/ios-dev.h
    +++ b/libpoke/ios-dev.h
    @@ -79,4 +79,9 @@ struct ios_dev_if
       /* Return the size of the device, in bytes.  */
     
       ios_dev_off (*size) (void *dev);
    +
    +  /* If called on a in-stream, free the buffer before OFFSET.  If called on
    +     an out-stream, flush the data till OFFSET and free the buffer before
    +     OFFSET.  Otherwise, do not do anything.  */
    +  int (*flush) (void *dev, ios_dev_off offset);
     };
    diff --git a/libpoke/ios.c b/libpoke/ios.c
    index 217e96c6..36fc88e4 100644
    --- a/libpoke/ios.c
    +++ b/libpoke/ios.c
    @@ -1517,3 +1517,9 @@ ios_size (ios io)
     {
       return io->dev_if->size (io->dev) * 8;
     }
    +
    +int
    +ios_flush (ios io, ios_off offset)
    +{
    +  return io->dev_if->flush (io->dev, offset);
    +}
    diff --git a/libpoke/ios.h b/libpoke/ios.h
    index 5c1f59ef..ab44ac68 100644
    --- a/libpoke/ios.h
    +++ b/libpoke/ios.h
    @@ -352,6 +352,14 @@ int ios_write_string (ios io, ios_off offset, int 
flags,
                           const char *value)
       __attribute__ ((visibility ("hidden")));
     
    +/* If the current IOD is a write stream, write out the data in the buffer
    +   till OFFSET.  If the current IOD is a stream IOD, free (if allowed by 
the
    +   embedded buffering strategy) bytes up to OFFSET.  This function has no
    +   impact when called on other IO devices.  */
    +
    +int ios_flush (ios io, ios_off offset)
    +  __attribute__ ((visibility ("hidden")));
    +
     /* **************** Update API **************** */
     
     /* XXX: writeme.  */