Re: [Qemu-devel] [PATCH V2 3/6] libqblock error handling

[Blue Swirl]

On Mon, Sep 10, 2012 at 8:26 AM, Wenchao Xia <address@hidden> wrote:
>   This patch contains error handling APIs, which user could call them to
> get error details.
>
> Signed-off-by: Wenchao Xia <address@hidden>
> ---
>  libqblock/libqblock-error.c |   60 
> +++++++++++++++++++++++++++++++++++++++++++
>  libqblock/libqblock-error.h |   50 +++++++++++++++++++++++++++++++++++
>  2 files changed, 110 insertions(+), 0 deletions(-)
>  create mode 100644 libqblock/libqblock-error.c
>  create mode 100644 libqblock/libqblock-error.h
>
> diff --git a/libqblock/libqblock-error.c b/libqblock/libqblock-error.c
> new file mode 100644
> index 0000000..d5ebabf
> --- /dev/null
> +++ b/libqblock/libqblock-error.c
> @@ -0,0 +1,60 @@
> +/*
> + * QEMU block layer library
> + *
> + * Copyright IBM, Corp. 2012
> + *
> + * Authors:
> + *  Wenchao Xia   <address@hidden>
> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2 or later.
> + * See the COPYING.LIB file in the top-level directory.
> + *
> + */
> +
> +#include "libqblock-error.h"
> +#include "libqblock-internal.h"
> +
> +void qb_error_get_human_str(struct QBroker *broker,
> +                            char *buf, int buf_size)

size_t buf_size

> +{
> +    const char *err_ret_str;
> +    switch (broker->err_ret) {
> +    case QB_ERR_MEM_ERR:
> +        err_ret_str = "Not enough memory.";
> +        break;
> +    case QB_ERR_INTERNAL_ERR:
> +        err_ret_str = "Internal error.";
> +        break;
> +    case QB_ERR_INVALID_PARAM:
> +        err_ret_str = "Invalid param.";
> +        break;
> +    case QB_ERR_BLOCK_OUT_OF_RANGE:
> +        err_ret_str = "request is out of image's range.";
> +        break;
> +    default:
> +        err_ret_str = "Unknow error.";
> +        break;
> +    }
> +    if (broker == NULL) {
> +        snprintf(buf, buf_size, "%s", err_ret_str);
> +        return;
> +    }
> +
> +    if (broker->err_ret == QB_ERR_INTERNAL_ERR) {
> +        snprintf(buf, buf_size, "%s %s errno [%d]. strerror [%s].",
> +                     err_ret_str, broker->err_msg,
> +                     broker->err_no, strerror(-broker->err_no));
> +    } else {
> +        snprintf(buf, buf_size, "%s %s",
> +                     err_ret_str, broker->err_msg);
> +    }

Please NUL terminate the string.

> +    return;
> +}
> +
> +int qb_error_get_errno(struct QBroker *broker)
> +{
> +    if (broker->err_ret == QB_ERR_INTERNAL_ERR) {
> +        return broker->err_no;
> +    }
> +    return 0;
> +}
> diff --git a/libqblock/libqblock-error.h b/libqblock/libqblock-error.h
> new file mode 100644
> index 0000000..0690cfb
> --- /dev/null
> +++ b/libqblock/libqblock-error.h
> @@ -0,0 +1,50 @@
> +/*
> + * QEMU block layer library
> + *
> + * Copyright IBM, Corp. 2012
> + *
> + * Authors:
> + *  Wenchao Xia   <address@hidden>
> + *
> + * This work is licensed under the terms of the GNU LGPL, version 2 or later.
> + * See the COPYING.LIB file in the top-level directory.
> + *
> + */
> +
> +#ifndef LIBQBLOCK_ERROR
> +#define LIBQBLOCK_ERROR
> +
> +#include "libqblock-types.h"
> +
> +#define QB_ERR_MEM_ERR (-1)
> +#define QB_ERR_INTERNAL_ERR (-2)
> +#define QB_ERR_INVALID_PARAM (-3)
> +#define QB_ERR_BLOCK_OUT_OF_RANGE (-100)
> +
> +/* error handling */
> +/**
> + * qb_error_get_human_str: get human readable error string.
> + *
> + * return a human readable string, it would be truncated if buf is not big
> + *  enough.
> + *
> + * @broker: operation broker, must be valid.
> + * @buf: buf to receive the string.
> + * @buf_size: the size of the string buf.
> + */
> +DLL_PUBLIC
> +void qb_error_get_human_str(struct QBroker *broker,
> +                            char *buf, int buf_size);
> +
> +/**
> + * qb_error_get_errno: get error number, only valid when err_ret is
> + *   QB_ERR_INTERNAL_ERR.
> + *
> + * return negative errno or 0 if last error is not QB_ERR_INTERNAL_ERR.
> + *
> + * @broker: operation broker.
> + */
> +DLL_PUBLIC
> +int qb_error_get_errno(struct QBroker *broker);
> +
> +#endif
> --
> 1.7.1
>
>