Re: [Qemu-devel] [PATCH RFC 1/4] get rid of signed range

[Michael S. Tsirkin]

On Sat, Jun 14, 2014 at 12:48:56PM +0800, Hu Tao wrote:
> Signed-off-by: Hu Tao <address@hidden>

Breaks build with glib < 2.28.
Replaced free_full with foreach + free.

> ---
>  include/qemu/range.h               | 144 
> ++++++++++++-------------------------
>  qapi/string-input-visitor.c        | 116 +++++++++++++++++-------------
>  qapi/string-output-visitor.c       |  97 +++++++++++++------------
>  tests/test-string-input-visitor.c  |   4 +-
>  tests/test-string-output-visitor.c |   8 +--
>  5 files changed, 165 insertions(+), 204 deletions(-)
> 
> diff --git a/include/qemu/range.h b/include/qemu/range.h
> index 8879f8a..cfa021f 100644
> --- a/include/qemu/range.h
> +++ b/include/qemu/range.h
> @@ -61,127 +61,75 @@ static inline int ranges_overlap(uint64_t first1, 
> uint64_t len1,
>      return !(last2 < first1 || last1 < first2);
>  }
>  
> -typedef struct SignedRangeList SignedRangeList;
> -
> -typedef struct SignedRange {
> -    int64_t start;
> -    int64_t length;
> -
> -    QTAILQ_ENTRY(SignedRange) entry;
> -} SignedRange;
> -
> -QTAILQ_HEAD(SignedRangeList, SignedRange);
> -
> -static inline int64_t s_range_end(int64_t start, int64_t length)
> -{
> -    return start + length - 1;
> -}
> -
> -/* negative length or overflow */
> -static inline bool s_range_overflow(int64_t start, int64_t length)
> +/* 0,1 can merge with 1,2 but don't overlap */
> +static inline bool ranges_can_merge(Range *range1, Range *range2)
>  {
> -    return s_range_end(start, length) < start;
> +    return !(range1->end < range2->begin || range2->end < range1->begin);
>  }
>  
> -static inline SignedRange *s_range_new(int64_t start, int64_t length)
> +static inline int range_merge(Range *range1, Range *range2)
>  {
> -    SignedRange *range = NULL;
> -
> -    if (s_range_overflow(start, length)) {
> -        return NULL;
> +    if (ranges_can_merge(range1, range2)) {
> +        if (range1->end < range2->end) {
> +            range1->end = range2->end;
> +        }
> +        if (range1->begin > range2->begin) {
> +            range1->begin = range2->begin;
> +        }
> +        return 0;
>      }
>  
> -    range = g_malloc0(sizeof(*range));
> -    range->start = start;
> -    range->length = length;
> -
> -    return range;
> -}
> -
> -static inline void s_range_free(SignedRange *range)
> -{
> -    g_free(range);
> +    return -1;
>  }
>  
> -static inline bool s_range_overlap(int64_t start1, int64_t length1,
> -                                   int64_t start2, int64_t length2)
> +static inline GList *g_list_insert_sorted_merged(GList *list,
> +                                                 gpointer data,
> +                                                 GCompareFunc func)
>  {
> -    return !((start1 + length1) < start2 || (start2 + length2) < start1);
> -}
> +    GList *l, *next = NULL;
> +    Range *r, *nextr;
>  
> -static inline int s_range_join(SignedRange *range,
> -                               int64_t start, int64_t length)
> -{
> -    if (s_range_overflow(start, length)) {
> -        return -1;
> +    if (!list) {
> +        list = g_list_insert_sorted(list, data, func);
> +        return list;
>      }
>  
> -    if (s_range_overlap(range->start, range->length, start, length)) {
> -        int64_t end = s_range_end(range->start, range->length);
> -        if (end < s_range_end(start, length)) {
> -            end = s_range_end(start, length);
> +    nextr = data;
> +    l = list;
> +    while (l && l != next && nextr) {
> +        r = l->data;
> +        if (ranges_can_merge(r, nextr)) {
> +            range_merge(r, nextr);
> +            l = g_list_remove_link(l, next);
> +            next = g_list_next(l);
> +            if (next) {
> +                nextr = next->data;
> +            } else {
> +                nextr = NULL;
> +            }
> +        } else {
> +            l = g_list_next(l);
>          }
> -        if (range->start > start) {
> -            range->start = start;
> -        }
> -        range->length = end - range->start + 1;
> -        return 0;
>      }
>  
> -    return -1;
> +    if (!l) {
> +        list = g_list_insert_sorted(list, data, func);
> +    }
> +
> +    return list;
>  }
>  
> -static inline int s_range_compare(int64_t start1, int64_t length1,
> -                                  int64_t start2, int64_t length2)
> +static inline gint range_compare(gconstpointer a, gconstpointer b)
>  {
> -    if (start1 == start2 && length1 == length2) {
> +    Range *ra = (Range *)a, *rb = (Range *)b;
> +    if (ra->begin == rb->begin && ra->end == rb->end) {
>          return 0;
> -    } else if (s_range_end(start1, length1) <
> -               s_range_end(start2, length2)) {
> +    } else if (range_get_last(ra->begin, ra->end) <
> +               range_get_last(rb->begin, rb->end)) {
>          return -1;
>      } else {
>          return 1;
>      }
>  }
>  
> -/* Add range to list. Keep them sorted, and merge ranges whenever possible */
> -static inline bool range_list_add(SignedRangeList *list,
> -                                  int64_t start, int64_t length)
> -{
> -    SignedRange *r, *next, *new_range = NULL, *cur = NULL;
> -
> -    if (s_range_overflow(start, length)) {
> -        return false;
> -    }
> -
> -    QTAILQ_FOREACH_SAFE(r, list, entry, next) {
> -        if (s_range_overlap(r->start, r->length, start, length)) {
> -            s_range_join(r, start, length);
> -            break;
> -        } else if (s_range_compare(start, length, r->start, r->length) < 0) {
> -            cur = r;
> -            break;
> -        }
> -    }
> -
> -    if (!r) {
> -        new_range = s_range_new(start, length);
> -        QTAILQ_INSERT_TAIL(list, new_range, entry);
> -    } else if (cur) {
> -        new_range = s_range_new(start, length);
> -        QTAILQ_INSERT_BEFORE(cur, new_range, entry);
> -    } else {
> -        SignedRange *next = QTAILQ_NEXT(r, entry);
> -        while (next && s_range_overlap(r->start, r->length,
> -                                       next->start, next->length)) {
> -            s_range_join(r, next->start, next->length);
> -            QTAILQ_REMOVE(list, next, entry);
> -            s_range_free(next);
> -            next = QTAILQ_NEXT(r, entry);
> -        }
> -    }
> -
> -    return true;
> -}
> -
>  #endif
> diff --git a/qapi/string-input-visitor.c b/qapi/string-input-visitor.c
> index 85ac6a1..0b2490b 100644
> --- a/qapi/string-input-visitor.c
> +++ b/qapi/string-input-visitor.c
> @@ -25,8 +25,8 @@ struct StringInputVisitor
>  
>      bool head;
>  
> -    SignedRangeList *ranges;
> -    SignedRange *cur_range;
> +    GList *ranges;
> +    GList *cur_range;
>      int64_t cur;
>  
>      const char *string;
> @@ -36,24 +36,25 @@ static void parse_str(StringInputVisitor *siv, Error 
> **errp)
>  {
>      char *str = (char *) siv->string;
>      long long start, end;
> -    SignedRange *r, *next;
> +    Range *cur;
>      char *endptr;
>  
>      if (siv->ranges) {
>          return;
>      }
>  
> -    siv->ranges = g_malloc0(sizeof(*siv->ranges));
> -    QTAILQ_INIT(siv->ranges);
>      errno = 0;
>      do {
>          start = strtoll(str, &endptr, 0);
>          if (errno == 0 && endptr > str && INT64_MIN <= start &&
>              start <= INT64_MAX) {
>              if (*endptr == '\0') {
> -                if (!range_list_add(siv->ranges, start, 1)) {
> -                    goto error;
> -                }
> +                cur = g_malloc0(sizeof(*cur));
> +                cur->begin = start;
> +                cur->end = start + 1;
> +                siv->ranges = g_list_insert_sorted_merged(siv->ranges, cur,
> +                                                          range_compare);
> +                cur = NULL;
>                  str = NULL;
>              } else if (*endptr == '-') {
>                  str = endptr + 1;
> @@ -63,17 +64,25 @@ static void parse_str(StringInputVisitor *siv, Error 
> **errp)
>                      (start > INT64_MAX - 65536 ||
>                       end < start + 65536)) {
>                      if (*endptr == '\0') {
> -                        if (!range_list_add(siv->ranges, start,
> -                                            end - start + 1)) {
> -                            goto error;
> -                        }
> +                        cur = g_malloc0(sizeof(*cur));
> +                        cur->begin = start;
> +                        cur->end = end + 1;
> +                        siv->ranges =
> +                            g_list_insert_sorted_merged(siv->ranges,
> +                                                        cur,
> +                                                        range_compare);
> +                        cur = NULL;
>                          str = NULL;
>                      } else if (*endptr == ',') {
>                          str = endptr + 1;
> -                        if (!range_list_add(siv->ranges, start,
> -                                            end - start + 1)) {
> -                            goto error;
> -                        }
> +                        cur = g_malloc0(sizeof(*cur));
> +                        cur->begin = start;
> +                        cur->end = end + 1;
> +                        siv->ranges =
> +                            g_list_insert_sorted_merged(siv->ranges,
> +                                                        cur,
> +                                                        range_compare);
> +                        cur = NULL;
>                      } else {
>                          goto error;
>                      }
> @@ -82,9 +91,13 @@ static void parse_str(StringInputVisitor *siv, Error 
> **errp)
>                  }
>              } else if (*endptr == ',') {
>                  str = endptr + 1;
> -                if (!range_list_add(siv->ranges, start, 1)) {
> -                    goto error;
> -                }
> +                cur = g_malloc0(sizeof(*cur));
> +                cur->begin = start;
> +                cur->end = start + 1;
> +                siv->ranges = g_list_insert_sorted_merged(siv->ranges,
> +                                                          cur,
> +                                                          range_compare);
> +                cur = NULL;
>              } else {
>                  goto error;
>              }
> @@ -95,14 +108,8 @@ static void parse_str(StringInputVisitor *siv, Error 
> **errp)
>  
>      return;
>  error:
> -    if (siv->ranges) {
> -        QTAILQ_FOREACH_SAFE(r, siv->ranges, entry, next) {
> -            QTAILQ_REMOVE(siv->ranges, r, entry);
> -            g_free(r);
> -        }
> -        g_free(siv->ranges);
> -        siv->ranges = NULL;
> -    }
> +    g_list_free_full(siv->ranges, g_free);
> +    assert(siv->ranges == NULL);
>  }
>  
>  static void
> @@ -112,10 +119,11 @@ start_list(Visitor *v, const char *name, Error **errp)
>  
>      parse_str(siv, errp);
>  
> -    if (siv->ranges) {
> -        siv->cur_range = QTAILQ_FIRST(siv->ranges);
> -        if (siv->cur_range) {
> -            siv->cur = siv->cur_range->start;
> +    siv->cur_range = g_list_first(siv->ranges);
> +    if (siv->cur_range) {
> +        Range *r = siv->cur_range->data;
> +        if (r) {
> +            siv->cur = r->begin;
>          }
>      }
>  }
> @@ -125,19 +133,27 @@ next_list(Visitor *v, GenericList **list, Error **errp)
>  {
>      StringInputVisitor *siv = DO_UPCAST(StringInputVisitor, visitor, v);
>      GenericList **link;
> +    Range *r;
>  
>      if (!siv->ranges || !siv->cur_range) {
>          return NULL;
>      }
>  
> -    if (siv->cur < siv->cur_range->start ||
> -        siv->cur >= (siv->cur_range->start + siv->cur_range->length)) {
> -        siv->cur_range = QTAILQ_NEXT(siv->cur_range, entry);
> -        if (siv->cur_range) {
> -            siv->cur = siv->cur_range->start;
> -        } else {
> +    r = siv->cur_range->data;
> +    if (!r) {
> +        return NULL;
> +    }
> +
> +    if (siv->cur < r->begin || siv->cur >= r->end) {
> +        siv->cur_range = g_list_next(siv->cur_range);
> +        if (!siv->cur_range) {
>              return NULL;
>          }
> +        r = siv->cur_range->data;
> +        if (!r) {
> +            return NULL;
> +        }
> +        siv->cur = r->begin;
>      }
>  
>      if (siv->head) {
> @@ -176,12 +192,19 @@ static void parse_type_int(Visitor *v, int64_t *obj, 
> const char *name,
>      }
>  
>      if (!siv->cur_range) {
> -        siv->cur_range = QTAILQ_FIRST(siv->ranges);
> -        if (siv->cur_range) {
> -            siv->cur = siv->cur_range->start;
> -        } else {
> +        Range *r;
> +
> +        siv->cur_range = g_list_first(siv->ranges);
> +        if (!siv->cur_range) {
> +            goto error;
> +        }
> +
> +        r = siv->cur_range->data;
> +        if (!r) {
>              goto error;
>          }
> +
> +        siv->cur = r->begin;
>      }
>  
>      *obj = siv->cur;
> @@ -291,16 +314,7 @@ Visitor *string_input_get_visitor(StringInputVisitor *v)
>  
>  void string_input_visitor_cleanup(StringInputVisitor *v)
>  {
> -    SignedRange *r, *next;
> -
> -    if (v->ranges) {
> -        QTAILQ_FOREACH_SAFE(r, v->ranges, entry, next) {
> -            QTAILQ_REMOVE(v->ranges, r, entry);
> -            g_free(r);
> -        }
> -        g_free(v->ranges);
> -    }
> -
> +    g_list_free_full(v->ranges, g_free);
>      g_free(v);
>  }
>  
> diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c
> index ccebc7a..1c0834a 100644
> --- a/qapi/string-output-visitor.c
> +++ b/qapi/string-output-visitor.c
> @@ -64,7 +64,7 @@ struct StringOutputVisitor
>          int64_t s;
>          uint64_t u;
>      } range_start, range_end;
> -    SignedRangeList *ranges;
> +    GList *ranges;
>  };
>  
>  static void string_output_set(StringOutputVisitor *sov, char *string)
> @@ -78,25 +78,50 @@ static void string_output_set(StringOutputVisitor *sov, 
> char *string)
>  
>  static void string_output_append(StringOutputVisitor *sov, int64_t a)
>  {
> -    range_list_add(sov->ranges, a, 1);
> +    Range *r = g_malloc0(sizeof(*r));
> +    r->begin = a;
> +    r->end = a + 1;
> +    sov->ranges = g_list_insert_sorted_merged(sov->ranges, r, range_compare);
>  }
>  
>  static void string_output_append_range(StringOutputVisitor *sov,
>                                         int64_t s, int64_t e)
>  {
> -    range_list_add(sov->ranges, s, e);
> +    Range *r = g_malloc0(sizeof(*r));
> +    r->begin = s;
> +    r->end = e + 1;
> +    sov->ranges = g_list_insert_sorted_merged(sov->ranges, r, range_compare);
> +}
> +
> +static void format_string(StringOutputVisitor *sov, Range *r, bool next,
> +                          bool human)
> +{
> +    if (r->end - r->begin > 1) {
> +        if (human) {
> +            g_string_append_printf(sov->string, "%" PRIx64 "-%" PRIx64,
> +                                   r->begin, r->end - 1);
> +
> +        } else {
> +            g_string_append_printf(sov->string, "%" PRId64 "-%" PRId64,
> +                                   r->begin, r->end - 1);
> +        }
> +    } else {
> +        if (human) {
> +            g_string_append_printf(sov->string, "%" PRIx64, r->begin);
> +        } else {
> +            g_string_append_printf(sov->string, "%" PRId64, r->begin);
> +        }
> +    }
> +    if (next) {
> +        g_string_append(sov->string, ",");
> +    }
>  }
>  
>  static void print_type_int(Visitor *v, int64_t *obj, const char *name,
>                             Error **errp)
>  {
>      StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
> -    SignedRange *r;
> -
> -    if (!sov->ranges) {
> -        sov->ranges = g_malloc0(sizeof(*sov->ranges));
> -        QTAILQ_INIT(sov->ranges);
> -    }
> +    GList *l;
>  
>      switch (sov->list_mode) {
>      case LM_NONE:
> @@ -118,8 +143,7 @@ static void print_type_int(Visitor *v, int64_t *obj, 
> const char *name,
>              } else {
>                  assert(sov->range_start.s < sov->range_end.s);
>                  string_output_append_range(sov, sov->range_start.s,
> -                                           sov->range_end.s -
> -                                           sov->range_start.s + 1);
> +                                           sov->range_end.s);
>              }
>  
>              sov->range_start.s = *obj;
> @@ -132,8 +156,7 @@ static void print_type_int(Visitor *v, int64_t *obj, 
> const char *name,
>              sov->range_end.s++;
>              assert(sov->range_start.s < sov->range_end.s);
>              string_output_append_range(sov, sov->range_start.s,
> -                                       sov->range_end.s -
> -                                       sov->range_start.s + 1);
> +                                       sov->range_end.s);
>          } else {
>              if (sov->range_start.s == sov->range_end.s) {
>                  string_output_append(sov, sov->range_end.s);
> @@ -141,8 +164,7 @@ static void print_type_int(Visitor *v, int64_t *obj, 
> const char *name,
>                  assert(sov->range_start.s < sov->range_end.s);
>  
>                  string_output_append_range(sov, sov->range_start.s,
> -                                           sov->range_end.s -
> -                                           sov->range_start.s + 1);
> +                                           sov->range_end.s);
>              }
>              string_output_append(sov, *obj);
>          }
> @@ -152,34 +174,20 @@ static void print_type_int(Visitor *v, int64_t *obj, 
> const char *name,
>          abort();
>      }
>  
> -    QTAILQ_FOREACH(r, sov->ranges, entry) {
> -        if (r->length > 1) {
> -            g_string_append_printf(sov->string, "%" PRId64 "-%" PRId64,
> -                                   r->start,
> -                                   s_range_end(r->start, r->length));
> -        } else {
> -            g_string_append_printf(sov->string, "%" PRId64,
> -                                   r->start);
> -        }
> -        if (r->entry.tqe_next) {
> -            g_string_append(sov->string, ",");
> -        }
> +    l = sov->ranges;
> +    while (l) {
> +        Range *r = l->data;
> +        format_string(sov, r, l->next != NULL, false);
> +        l = l->next;
>      }
>  
>      if (sov->human) {
> +        l = sov->ranges;
>          g_string_append(sov->string, " (");
> -        QTAILQ_FOREACH(r, sov->ranges, entry) {
> -            if (r->length > 1) {
> -                g_string_append_printf(sov->string, "%" PRIx64 "-%" PRIx64,
> -                                       r->start,
> -                                       s_range_end(r->start, r->length));
> -            } else {
> -                g_string_append_printf(sov->string, "%" PRIx64,
> -                                       r->start);
> -            }
> -            if (r->entry.tqe_next) {
> -                g_string_append(sov->string, ",");
> -            }
> +        while (l) {
> +            Range *r = l->data;
> +            format_string(sov, r, l->next != NULL, false);
> +            l = l->next;
>          }
>          g_string_append(sov->string, ")");
>      }
> @@ -310,20 +318,11 @@ Visitor *string_output_get_visitor(StringOutputVisitor 
> *sov)
>  
>  void string_output_visitor_cleanup(StringOutputVisitor *sov)
>  {
> -    SignedRange *r, *next;
> -
>      if (sov->string) {
>          g_string_free(sov->string, true);
>      }
>  
> -    if (sov->ranges) {
> -        QTAILQ_FOREACH_SAFE(r, sov->ranges, entry, next) {
> -            QTAILQ_REMOVE(sov->ranges, r, entry);
> -            s_range_free(r);
> -        }
> -        g_free(sov->ranges);
> -    }
> -
> +    g_list_free_full(sov->ranges, g_free);
>      g_free(sov);
>  }
>  
> diff --git a/tests/test-string-input-visitor.c 
> b/tests/test-string-input-visitor.c
> index b08a7db..b01e2f2 100644
> --- a/tests/test-string-input-visitor.c
> +++ b/tests/test-string-input-visitor.c
> @@ -67,13 +67,13 @@ static void test_visitor_in_int(TestInputVisitorData 
> *data,
>  static void test_visitor_in_intList(TestInputVisitorData *data,
>                                      const void *unused)
>  {
> -    int64_t value[] = {-2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 20};
> +    int64_t value[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 20};
>      int16List *res = NULL, *tmp;
>      Error *errp = NULL;
>      Visitor *v;
>      int i = 0;
>  
> -    v = visitor_input_test_init(data, "1,2,-2-1,2-4,20,5-9,1-8");
> +    v = visitor_input_test_init(data, "1,2,0,2-4,20,5-9,1-8");
>  
>      visit_type_int16List(v, &res, NULL, &errp);
>      g_assert(errp == NULL);
> diff --git a/tests/test-string-output-visitor.c 
> b/tests/test-string-output-visitor.c
> index d2ad580..28e7359 100644
> --- a/tests/test-string-output-visitor.c
> +++ b/tests/test-string-output-visitor.c
> @@ -44,7 +44,7 @@ static void visitor_output_teardown(TestOutputVisitorData 
> *data,
>  static void test_visitor_out_int(TestOutputVisitorData *data,
>                                   const void *unused)
>  {
> -    int64_t value = -42;
> +    int64_t value = 42;
>      Error *err = NULL;
>      char *str;
>  
> @@ -53,14 +53,14 @@ static void test_visitor_out_int(TestOutputVisitorData 
> *data,
>  
>      str = string_output_get_string(data->sov);
>      g_assert(str != NULL);
> -    g_assert_cmpstr(str, ==, "-42");
> +    g_assert_cmpstr(str, ==, "42");
>      g_free(str);
>  }
>  
>  static void test_visitor_out_intList(TestOutputVisitorData *data,
>                                       const void *unused)
>  {
> -    int64_t value[] = {-10, -7, -2, -1, 0, 1, 9, 10, 16, 15, 14,
> +    int64_t value[] = {0, 1, 9, 10, 16, 15, 14,
>          3, 4, 5, 6, 11, 12, 13, 21, 22, INT64_MAX - 1, INT64_MAX};
>      intList *list = NULL, **tmp = &list;
>      int i;
> @@ -79,7 +79,7 @@ static void test_visitor_out_intList(TestOutputVisitorData 
> *data,
>      str = string_output_get_string(data->sov);
>      g_assert(str != NULL);
>      g_assert_cmpstr(str, ==,
> -        
> "-10,-7,-2-1,3-6,9-16,21-22,9223372036854775806-9223372036854775807");
> +        "0-1,3-6,9-16,21-22,9223372036854775806-9223372036854775807");
>      g_free(str);
>      while (list) {
>          intList *tmp2;
> -- 
> 1.9.3