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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:51:24 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:51:24 +0000 |
commit | f7548d6d28c313cf80e6f3ef89aed16a19815df1 (patch) | |
tree | a3f6f2a3f247293bee59ecd28e8cd8ceb6ca064a /src/lib/seq-range-array.c | |
parent | Initial commit. (diff) | |
download | dovecot-f7548d6d28c313cf80e6f3ef89aed16a19815df1.tar.xz dovecot-f7548d6d28c313cf80e6f3ef89aed16a19815df1.zip |
Adding upstream version 1:2.3.19.1+dfsg1.upstream/1%2.3.19.1+dfsg1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/lib/seq-range-array.c | 569 |
1 files changed, 569 insertions, 0 deletions
diff --git a/src/lib/seq-range-array.c b/src/lib/seq-range-array.c new file mode 100644 index 0000000..2d8dbfc --- /dev/null +++ b/src/lib/seq-range-array.c @@ -0,0 +1,569 @@ +/* Copyright (c) 2005-2018 Dovecot authors, see the included COPYING file */ + +#include "lib.h" +#include "array.h" +#include "seq-range-array.h" + +static bool seq_range_is_overflowed(const ARRAY_TYPE(seq_range) *array) +{ + const struct seq_range *range; + unsigned int count; + + range = array_get(array, &count); + return count == 1 && range[0].seq1 == 0 && + range[0].seq2 == (uint32_t)-1; +} + +static bool ATTR_NOWARN_UNUSED_RESULT +seq_range_lookup(const ARRAY_TYPE(seq_range) *array, + uint32_t seq, unsigned int *idx_r) +{ + const struct seq_range *data; + unsigned int idx, left_idx, right_idx, count; + + data = array_get(array, &count); + i_assert(count < INT_MAX); + + idx = 0; left_idx = 0; right_idx = count; + while (left_idx < right_idx) { + idx = (left_idx + right_idx) / 2; + + if (data[idx].seq1 <= seq) { + if (data[idx].seq2 >= seq) { + /* it's already in the range */ + *idx_r = idx; + return TRUE; + } + left_idx = idx+1; + } else { + right_idx = idx; + } + } + if (left_idx > idx) + idx++; + *idx_r = idx; + return FALSE; +} + +static bool +seq_range_array_add_slow_path(ARRAY_TYPE(seq_range) *array, uint32_t seq) +{ + struct seq_range *data, value; + unsigned int idx, count; + + value.seq1 = value.seq2 = seq; + data = array_get_modifiable(array, &count); + + /* somewhere in the middle, array is sorted so find it with + binary search */ + if (seq_range_lookup(array, seq, &idx)) + return TRUE; + + /* idx == count couldn't happen because we already handle it above */ + i_assert(idx < count && data[idx].seq1 >= seq); + i_assert(data[idx].seq1 > seq || data[idx].seq2 < seq); + + if (data[idx].seq1 == seq+1) { + data[idx].seq1 = seq; + if (idx > 0 && data[idx-1].seq2 == seq-1) { + /* merge */ + data[idx-1].seq2 = data[idx].seq2; + array_delete(array, idx, 1); + } + } else { + if (idx > 0 && data[idx-1].seq2 == seq-1) + idx--; + if (data[idx].seq2 == seq-1) { + i_assert(idx+1 < count); /* already handled above */ + data[idx].seq2 = seq; + if (data[idx+1].seq1 == seq+1) { + /* merge */ + data[idx+1].seq1 = data[idx].seq1; + array_delete(array, idx, 1); + } + } else { + array_insert(array, idx, &value, 1); + } + } + return FALSE; +} + +bool seq_range_array_add(ARRAY_TYPE(seq_range) *array, uint32_t seq) +{ + struct seq_range *data, value; + unsigned int count; + bool exists = FALSE; + + value.seq1 = value.seq2 = seq; + + data = array_get_modifiable(array, &count); + /* quick checks */ + if (count == 0) + array_push_back(array, &value); + else if (data[count-1].seq2 < seq) { + if (data[count-1].seq2 == seq-1) { + /* grow last range */ + data[count-1].seq2 = seq; + } else { + array_push_back(array, &value); + } + } else if (data[0].seq1 > seq) { + if (data[0].seq1-1 == seq) { + /* grow down first range */ + data[0].seq1 = seq; + } else { + array_push_front(array, &value); + } + } else { + exists = seq_range_array_add_slow_path(array, seq); + } + i_assert(!seq_range_is_overflowed(array)); + return exists; +} + +void seq_range_array_add_with_init(ARRAY_TYPE(seq_range) *array, + unsigned int init_count, uint32_t seq) +{ + if (!array_is_created(array)) + i_array_init(array, init_count); + seq_range_array_add(array, seq); +} + +static void +seq_range_array_add_range_internal(ARRAY_TYPE(seq_range) *array, + uint32_t seq1, uint32_t seq2, + unsigned int *r_count) +{ + struct seq_range *data, value; + unsigned int idx1, idx2, count; + + seq_range_lookup(array, seq1, &idx1); + seq_range_lookup(array, seq2, &idx2); + + data = array_get_modifiable(array, &count); + if (r_count != NULL) { + /* Find number we're adding by counting the number we're + not adding, and subtracting that from the nominal range. */ + unsigned int added = seq2+1 - seq1; + unsigned int countidx2 = idx2; + unsigned int overcounted = 0u, notadded = 0u; + unsigned int i; + + if (idx1 == count) { + /* not in a range as too far right */ + } else if (seq1 < data[idx1].seq1) { + /* not in a range, to the left of a real range */ + } else { + /* count the whole of this range, which is an overcount */ + overcounted += seq1 - data[idx1].seq1; + /* fencepost check: equality means the whole range is valid, + therefore there's no overcounting. Result = 0 overcount */ + } + if (idx2 == count) { + /* not in a range as too far right */ + } else if (seq2 < data[idx2].seq1) { + /* not in a range, to the left of a real range */ + } else { + /* count the whole of this range, which is an overcount */ + overcounted += data[idx2].seq2 - seq2; + countidx2++; /* may become == count i.e. past the end */ + /* fencepost check: equality means the whole range is valid, + therefore there's no overcounting. Result = 0 overcount. */ + } + /* Now count how many we're not adding */ + for (i = idx1; i < countidx2; i++) + notadded += data[i].seq2+1 - data[i].seq1; + /* Maybe the not added tally included some over-counting too */ + added -= (notadded - overcounted); + *r_count = added; + } + + if (idx1 > 0 && data[idx1-1].seq2+1 == seq1) + idx1--; + + if (idx1 == idx2 && + (idx2 == count || (seq2 < (uint32_t)-1 && data[idx2].seq1 > seq2+1)) && + (idx1 == 0 || data[idx1-1].seq2 < seq1-1)) { + /* no overlapping */ + value.seq1 = seq1; + value.seq2 = seq2; + array_insert(array, idx1, &value, 1); + } else { + i_assert(idx1 < count); + if (seq1 < data[idx1].seq1) + data[idx1].seq1 = seq1; + if (seq2 > data[idx1].seq2) { + /* merge */ + if (idx2 == count || + data[idx2].seq1 > seq2+1) + idx2--; + if (seq2 >= data[idx2].seq2) { + data[idx1].seq2 = seq2; + } else { + data[idx1].seq2 = data[idx2].seq2; + } + array_delete(array, idx1 + 1, idx2 - idx1); + } + } + i_assert(!seq_range_is_overflowed(array)); +} + +void seq_range_array_add_range(ARRAY_TYPE(seq_range) *array, + uint32_t seq1, uint32_t seq2) +{ + seq_range_array_add_range_internal(array, seq1, seq2, NULL); +} +unsigned int seq_range_array_add_range_count(ARRAY_TYPE(seq_range) *array, + uint32_t seq1, uint32_t seq2) +{ + unsigned int count; + seq_range_array_add_range_internal(array, seq1, seq2, &count); + return count; +} + +void seq_range_array_merge(ARRAY_TYPE(seq_range) *dest, + const ARRAY_TYPE(seq_range) *src) +{ + const struct seq_range *range; + + if (array_count(dest) == 0) { + array_append_array(dest, src); + return; + } + + array_foreach(src, range) + seq_range_array_add_range(dest, range->seq1, range->seq2); +} + +void seq_range_array_merge_n(ARRAY_TYPE(seq_range) *dest, + const ARRAY_TYPE(seq_range) *src, + unsigned int count) +{ + const struct seq_range *src_range; + unsigned int src_idx, src_count; + unsigned int merge_count = count; + + src_range = array_get(src, &src_count); + for (src_idx = 0; src_idx < src_count && merge_count > 0; src_idx++) { + uint32_t first_seq = src_range[src_idx].seq1; + uint32_t last_seq = src_range[src_idx].seq2; + unsigned int idx_count = last_seq - first_seq + 1; + + if (idx_count > merge_count) { + last_seq = first_seq + merge_count - 1; + merge_count = 0; + } else { + merge_count -= idx_count; + } + seq_range_array_add_range(dest, first_seq, last_seq); + } +} + +bool seq_range_array_remove(ARRAY_TYPE(seq_range) *array, uint32_t seq) +{ + struct seq_range *data, value; + unsigned int idx, left_idx, right_idx, count; + + if (!array_is_created(array)) + return FALSE; + + data = array_get_modifiable(array, &count); + if (count == 0) + return FALSE; + + /* quick checks */ + if (seq > data[count-1].seq2 || seq < data[0].seq1) { + /* outside the range */ + return FALSE; + } + if (data[count-1].seq2 == seq) { + /* shrink last range */ + if (data[count-1].seq1 != data[count-1].seq2) + data[count-1].seq2--; + else + array_delete(array, count-1, 1); + return TRUE; + } + if (data[0].seq1 == seq) { + /* shrink up first range */ + if (data[0].seq1 != data[0].seq2) + data[0].seq1++; + else + array_pop_front(array); + return TRUE; + } + + /* somewhere in the middle, array is sorted so find it with + binary search */ + i_assert(count < INT_MAX); + left_idx = 0; right_idx = count; + while (left_idx < right_idx) { + idx = (left_idx + right_idx) / 2; + + if (data[idx].seq1 > seq) + right_idx = idx; + else if (data[idx].seq2 < seq) + left_idx = idx+1; + else { + /* found it */ + if (data[idx].seq1 == seq) { + if (data[idx].seq1 == data[idx].seq2) { + /* a single sequence range. + remove it entirely */ + array_delete(array, idx, 1); + } else { + /* shrink the range */ + data[idx].seq1++; + } + } else if (data[idx].seq2 == seq) { + /* shrink the range */ + data[idx].seq2--; + } else { + /* split the sequence range */ + value.seq1 = seq + 1; + value.seq2 = data[idx].seq2; + data[idx].seq2 = seq - 1; + + array_insert(array, idx + 1, &value, 1); + } + return TRUE; + } + } + return FALSE; +} + +unsigned int seq_range_array_remove_range(ARRAY_TYPE(seq_range) *array, + uint32_t seq1, uint32_t seq2) +{ + const struct seq_range *data; + unsigned int idx, idx2, count, remove_count = 0; + + /* remove first and last. this makes sure that everything between + can simply be deleted with array_delete(). + + FIXME: it would be faster if we did only one binary lookup here + and handled the splitting ourself.. */ + if (seq_range_array_remove(array, seq1)) + remove_count++; + if (seq1 == seq2) + return remove_count; + seq1++; + + if (seq_range_array_remove(array, seq2--)) + remove_count++; + if (seq1 > seq2) + return remove_count; + + /* find the beginning */ + data = array_get(array, &count); + seq_range_lookup(array, seq1, &idx); + + if (idx == count) + return remove_count; + + i_assert(data[idx].seq1 >= seq1); + for (idx2 = idx; idx2 < count; idx2++) { + if (data[idx2].seq1 > seq2) + break; + i_assert(UINT_MAX - remove_count >= seq_range_length(&data[idx2])); + remove_count += seq_range_length(&data[idx2]); + } + array_delete(array, idx, idx2-idx); + return remove_count; +} + +unsigned int seq_range_array_remove_seq_range(ARRAY_TYPE(seq_range) *dest, + const ARRAY_TYPE(seq_range) *src) +{ + unsigned int count, full_count = 0; + const struct seq_range *src_range; + + array_foreach(src, src_range) { + count = seq_range_array_remove_range(dest, src_range->seq1, + src_range->seq2); + i_assert(UINT_MAX - full_count >= count); + full_count += count; + } + return full_count; +} + +void seq_range_array_remove_nth(ARRAY_TYPE(seq_range) *array, + uint32_t n, uint32_t count) +{ + struct seq_range_iter iter; + uint32_t seq1, seq2; + + if (count == 0) + return; + + seq_range_array_iter_init(&iter, array); + if (!seq_range_array_iter_nth(&iter, n, &seq1)) { + /* n points beyond array */ + return; + } + if (count-1 >= (uint32_t)-1 - n || + !seq_range_array_iter_nth(&iter, n + (count-1), &seq2)) { + /* count points beyond array */ + seq2 = (uint32_t)-1; + } + seq_range_array_remove_range(array, seq1, seq2); +} + +unsigned int seq_range_array_intersect(ARRAY_TYPE(seq_range) *dest, + const ARRAY_TYPE(seq_range) *src) +{ + const struct seq_range *src_range; + unsigned int i, count, remove_count, full_count = 0; + uint32_t last_seq = 0; + + src_range = array_get(src, &count); + for (i = 0; i < count; i++) { + if (last_seq + 1 < src_range[i].seq1) { + remove_count = seq_range_array_remove_range(dest, + last_seq + 1, src_range[i].seq1 - 1); + i_assert(UINT_MAX - full_count >= remove_count); + full_count += remove_count; + } + last_seq = src_range[i].seq2; + } + if (last_seq != (uint32_t)-1) { + remove_count = seq_range_array_remove_range(dest, last_seq + 1, + (uint32_t)-1); + i_assert(UINT_MAX - full_count >= remove_count); + full_count += remove_count; + } + return full_count; +} + +bool seq_range_exists(const ARRAY_TYPE(seq_range) *array, uint32_t seq) +{ + unsigned int idx; + + return seq_range_lookup(array, seq, &idx); +} + +bool seq_range_array_have_common(const ARRAY_TYPE(seq_range) *array1, + const ARRAY_TYPE(seq_range) *array2) +{ + const struct seq_range *range1, *range2; + unsigned int i1, i2, count1, count2; + + range1 = array_get(array1, &count1); + range2 = array_get(array2, &count2); + for (i1 = i2 = 0; i1 < count1 && i2 < count2; ) { + if (range1[i1].seq1 <= range2[i2].seq2 && + range1[i1].seq2 >= range2[i2].seq1) + return TRUE; + + if (range1[i1].seq1 < range2[i2].seq1) + i1++; + else + i2++; + } + return FALSE; +} + +unsigned int seq_range_count(const ARRAY_TYPE(seq_range) *array) +{ + const struct seq_range *range; + unsigned int seq_count = 0; + + array_foreach(array, range) { + i_assert(UINT_MAX - seq_count >= seq_range_length(range)); + seq_count += seq_range_length(range); + } + return seq_count; +} + +void seq_range_array_invert(ARRAY_TYPE(seq_range) *array, + uint32_t min_seq, uint32_t max_seq) +{ + struct seq_range *range, value; + unsigned int i, count; + uint32_t prev_min_seq; + + if (array_is_created(array)) + range = array_get_modifiable(array, &count); + else { + range = NULL; + count = 0; + } + if (count == 0) { + /* empty -> full */ + if (!array_is_created(array)) + i_array_init(array, 4); + value.seq1 = min_seq; + value.seq2 = max_seq; + array_push_back(array, &value); + return; + } + i_assert(range[0].seq1 >= min_seq); + i_assert(range[count-1].seq2 <= max_seq); + + if (range[0].seq1 == min_seq && range[0].seq2 == max_seq) { + /* full -> empty */ + array_clear(array); + return; + } + + for (i = 0; i < count; ) { + prev_min_seq = min_seq; + min_seq = range[i].seq2; + if (range[i].seq1 == prev_min_seq) { + array_delete(array, i, 1); + range = array_get_modifiable(array, &count); + } else { + range[i].seq2 = range[i].seq1 - 1; + range[i].seq1 = prev_min_seq; + i++; + } + if (min_seq >= max_seq) { + /* max_seq is reached. the rest of the array should be + empty. we'll return here, because min_seq++ may + wrap to 0. */ + i_assert(min_seq == max_seq); + i_assert(i == count); + return; + } + min_seq++; + } + if (min_seq <= max_seq) { + value.seq1 = min_seq; + value.seq2 = max_seq; + array_push_back(array, &value); + } +} + +void seq_range_array_iter_init(struct seq_range_iter *iter_r, + const ARRAY_TYPE(seq_range) *array) +{ + i_zero(iter_r); + iter_r->array = array; +} + +bool seq_range_array_iter_nth(struct seq_range_iter *iter, unsigned int n, + uint32_t *seq_r) +{ + const struct seq_range *range; + unsigned int i, count, diff; + + if (n < iter->prev_n) { + /* iterating backwards, don't bother optimizing */ + iter->prev_n = 0; + iter->prev_idx = 0; + } + + range = array_get(iter->array, &count); + for (i = iter->prev_idx; i < count; i++) { + diff = range[i].seq2 - range[i].seq1; + if (n <= iter->prev_n + diff) { + i_assert(n >= iter->prev_n); + *seq_r = range[i].seq1 + (n - iter->prev_n); + iter->prev_idx = i; + return TRUE; + } + iter->prev_n += diff + 1; + } + iter->prev_idx = i; + return FALSE; +} |