Re: [Qemu-devel] [PATCH v19 07/11] qapi: make string output visitor parse int list

[Paolo Bonzini <pbonzini@redhat.com>]

Il 04/03/2014 08:28, Hu Tao ha scritto:
> From: Hu Tao <hu.taoo@gmail.com>
>
> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
> ---
>  qapi/string-output-visitor.c       | 156 +++++++++++++++++++++++++++++++++++--
>  tests/test-string-output-visitor.c |  26 +++++++
>  2 files changed, 177 insertions(+), 5 deletions(-)
>
> diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c
> index fb1d2e8..bc9bb36 100644
> --- a/qapi/string-output-visitor.c
> +++ b/qapi/string-output-visitor.c
> @@ -17,11 +17,57 @@
>  #include "qemu/host-utils.h"
>  #include <math.h>
>
> +enum ListMode {
> +    LM_NONE,             /* not traversing a list of repeated options */
> +    LM_STARTED,          /* start_list() succeeded */
> +
> +    LM_IN_PROGRESS,      /* next_list() has been called.
> +                          *
> +                          * Generating the next list link will consume the most
> +                          * recently parsed QemuOpt instance of the repeated
> +                          * option.
> +                          *
> +                          * Parsing a value into the list link will examine the
> +                          * next QemuOpt instance of the repeated option, and
> +                          * possibly enter LM_SIGNED_INTERVAL or
> +                          * LM_UNSIGNED_INTERVAL.
> +                          */
> +
> +    LM_SIGNED_INTERVAL,  /* next_list() has been called.
> +                          *
> +                          * Generating the next list link will consume the most
> +                          * recently stored element from the signed interval,
> +                          * parsed from the most recent QemuOpt instance of the
> +                          * repeated option. This may consume QemuOpt itself
> +                          * and return to LM_IN_PROGRESS.
> +                          *
> +                          * Parsing a value into the list link will store the
> +                          * next element of the signed interval.
> +                          */
> +
> +    LM_UNSIGNED_INTERVAL,/* Same as above, only for an unsigned interval. */
> +
> +    LM_END
> +};
> +
> +typedef enum ListMode ListMode;
> +
>  struct StringOutputVisitor
>  {
>      Visitor visitor;
>      bool human;
> +    bool head;
>      char *string;
> +    ListMode list_mode;
> +    /* When parsing a list of repeating options as integers, values of the form
> +     * "a-b", representing a closed interval, are allowed. Elements in the
> +     * range are generated individually.
> +     */
> +    union {
> +        int64_t s;
> +        uint64_t u;
> +    } range_start, range_end;
> +
>  };
>
>  static void string_output_set(StringOutputVisitor *sov, char *string)
> @@ -34,13 +80,60 @@ static void print_type_int(Visitor *v, int64_t *obj, const char *name,
>                             Error **errp)
>  {
>      StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
> -    char *out;
> +    char *out = NULL;
>
> -    if (sov->human) {
> -        out = g_strdup_printf("%lld (%#llx)", (long long) *obj, (long long) *obj);
> -    } else {
> -        out = g_strdup_printf("%lld", (long long) *obj);
> +    switch (sov->list_mode) {
> +    case LM_NONE:
> +        if (sov->human) {
> +            out = g_strdup_printf("%lld (%#llx)", (long long) *obj,
> +                                  (long long) *obj);
> +        } else {
> +            out = g_strdup_printf("%lld", (long long) *obj);
> +        }
> +        sov->list_mode = LM_END;
> +        break;
> +
> +    case LM_STARTED:
> +        sov->range_start.s = *obj;
> +        sov->range_end.s = *obj;
> +        sov->list_mode = LM_IN_PROGRESS;
> +        break;
> +
> +    case LM_IN_PROGRESS:
> +        assert(sov->range_end.s + 1 == *obj);
> +        sov->range_end.s++;
> +        break;
> +
> +    case LM_END:
> +        assert(sov->range_end.s + 1 == *obj);
> +        sov->range_end.s++;
> +        if (sov->range_end.s == sov->range_start.s) {
> +            if (sov->human) {
> +                out = g_strdup_printf("%lld (%#llx)",
> +                                      (long long)sov->range_start.s,
> +                                      (long long)sov->range_start.s);
> +            } else {
> +                out = g_strdup_printf("%lld", (long long)sov->range_start.s);
> +            }
> +        } else {
> +            if (sov->human) {
> +                out = g_strdup_printf("%lld(%#llx)-%lld(%#llx)",
> +                                      (long long) sov->range_start.s,
> +                                      (long long) sov->range_start.s,
> +                                      (long long) sov->range_end.s,
> +                                      (long long) sov->range_end.s);

Perhaps "10-15 (0xa-0xf)"?

> +            } else {
> +                out = g_strdup_printf("%lld-%lld",
> +                                      (long long) sov->range_start.s,
> +                                      (long long) sov->range_end.s);
> +            }
> +        }

This looks wrong.  You do not insert any separator, and you do not 
handle things like "0-3,8-11".  You probably should use a GString 
instead of string_output_set.

Paolo

> +        break;
> +
> +    default:
> +        abort();
>      }
> +
>      string_output_set(sov, out);
>  }
>
> @@ -103,6 +196,56 @@ static void print_type_number(Visitor *v, double *obj, const char *name,
>      string_output_set(sov, g_strdup_printf("%f", *obj));
>  }
>
> +static void
> +start_list(Visitor *v, const char *name, Error **errp)
> +{
> +    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
> +
> +    /* we can't traverse a list in a list */
> +    assert(sov->list_mode == LM_NONE);
> +    sov->list_mode = LM_STARTED;
> +    sov->head = true;
> +}
> +
> +static GenericList *
> +next_list(Visitor *v, GenericList **list, Error **errp)
> +{
> +    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
> +    GenericList *ret = NULL;
> +    if (*list) {
> +        if (sov->head) {
> +            ret = *list;
> +        } else {
> +            ret = (*list)->next;
> +        }
> +
> +        if (sov->head) {
> +            if (ret && ret->next == NULL) {
> +                sov->list_mode = LM_NONE;
> +            }
> +            sov->head = false;
> +        } else {
> +            if (ret && ret->next == NULL) {
> +                sov->list_mode = LM_END;
> +            }
> +        }
> +    }
> +
> +    return ret;
> +}
> +
> +static void
> +end_list(Visitor *v, Error **errp)
> +{
> +    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
> +
> +    assert(sov->list_mode == LM_STARTED ||
> +           sov->list_mode == LM_END ||
> +           sov->list_mode == LM_IN_PROGRESS);
> +    sov->list_mode = LM_NONE;
> +    sov->head = true;
> +}
> +
>  char *string_output_get_string(StringOutputVisitor *sov)
>  {
>      char *string = sov->string;
> @@ -134,6 +277,9 @@ StringOutputVisitor *string_output_visitor_new(bool human)
>      v->visitor.type_bool = print_type_bool;
>      v->visitor.type_str = print_type_str;
>      v->visitor.type_number = print_type_number;
> +    v->visitor.start_list = start_list;
> +    v->visitor.next_list = next_list;
> +    v->visitor.end_list = end_list;
>
>      return v;
>  }
> diff --git a/tests/test-string-output-visitor.c b/tests/test-string-output-visitor.c
> index 22363d1..511ef14 100644
> --- a/tests/test-string-output-visitor.c
> +++ b/tests/test-string-output-visitor.c
> @@ -57,6 +57,30 @@ static void test_visitor_out_int(TestOutputVisitorData *data,
>      g_free(str);
>  }
>
> +static void test_visitor_out_intList(TestOutputVisitorData *data,
> +                                     const void *unused)
> +{
> +    int64_t value[] = {-2, -1, 0, 1, 2, 3, 4};
> +    intList *list = NULL, **tmp = &list;
> +    int i;
> +    Error *errp = NULL;
> +    char *str;
> +
> +    for (i = 0; i < sizeof(value) / sizeof(value[0]); i++) {
> +        *tmp = g_malloc0(sizeof(**tmp));
> +        (*tmp)->value = value[i];
> +        tmp = &(*tmp)->next;
> +    }
> +
> +    visit_type_intList(data->ov, &list, NULL, &errp);
> +    g_assert(error_is_set(&errp) == 0);
> +
> +    str = string_output_get_string(data->sov);
> +    g_assert(str != NULL);
> +    g_assert_cmpstr(str, ==, "-2-4");
> +    g_free(str);
> +}
> +
>  static void test_visitor_out_bool(TestOutputVisitorData *data,
>                                    const void *unused)
>  {
> @@ -182,6 +206,8 @@ int main(int argc, char **argv)
>                              &out_visitor_data, test_visitor_out_enum);
>      output_visitor_test_add("/string-visitor/output/enum-errors",
>                              &out_visitor_data, test_visitor_out_enum_errors);
> +    output_visitor_test_add("/string-visitor/output/intList",
> +                            &out_visitor_data, test_visitor_out_intList);
>
>      g_test_run();
>
>