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Hash :
8bdedb3b
Author :
Date :
2025-08-20T00:27:41
Limit external caches (#5483) * Revert "[external_cache] Remove a conditional (#5471)" This reverts commit 9794ad9e00ff66741c36ec9511e3e968663b74a7. * Limit external_cache to 8 subtables per lookup
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#ifndef OT_LAYOUT_GPOS_PAIRPOSFORMAT1_HH
#define OT_LAYOUT_GPOS_PAIRPOSFORMAT1_HH
#include "PairSet.hh"
namespace OT {
namespace Layout {
namespace GPOS_impl {
template <typename Types>
struct PairPosFormat1_3
{
using PairSet = GPOS_impl::PairSet<Types>;
using PairValueRecord = GPOS_impl::PairValueRecord<Types>;
protected:
HBUINT16 format; /* Format identifier--format = 1 */
typename Types::template OffsetTo<Coverage>
coverage; /* Offset to Coverage table--from
* beginning of subtable */
ValueFormat valueFormat[2]; /* [0] Defines the types of data in
* ValueRecord1--for the first glyph
* in the pair--may be zero (0) */
/* [1] Defines the types of data in
* ValueRecord2--for the second glyph
* in the pair--may be zero (0) */
Array16Of<typename Types::template OffsetTo<PairSet>>
pairSet; /* Array of PairSet tables
* ordered by Coverage Index */
public:
DEFINE_SIZE_ARRAY (8 + Types::size, pairSet);
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
if (!c->check_struct (this)) return_trace (false);
hb_barrier ();
unsigned int len1 = valueFormat[0].get_len ();
unsigned int len2 = valueFormat[1].get_len ();
typename PairSet::sanitize_closure_t closure =
{
valueFormat,
len1,
PairSet::get_size (len1, len2)
};
return_trace (coverage.sanitize (c, this) && pairSet.sanitize (c, this, &closure));
}
bool intersects (const hb_set_t *glyphs) const
{
auto &cov = this+coverage;
if (pairSet.len > glyphs->get_population () * hb_bit_storage ((unsigned) pairSet.len))
{
for (hb_codepoint_t g : glyphs->iter())
{
unsigned i = cov.get_coverage (g);
if ((this+pairSet[i]).intersects (glyphs, valueFormat))
return true;
}
return false;
}
return
+ hb_zip (cov, pairSet)
| hb_filter (*glyphs, hb_first)
| hb_map (hb_second)
| hb_map ([glyphs, this] (const typename Types::template OffsetTo<PairSet> &_)
{ return (this+_).intersects (glyphs, valueFormat); })
| hb_any
;
}
void closure_lookups (hb_closure_lookups_context_t *c) const {}
void collect_variation_indices (hb_collect_variation_indices_context_t *c) const
{
if ((!valueFormat[0].has_device ()) && (!valueFormat[1].has_device ())) return;
auto it =
+ hb_zip (this+coverage, pairSet)
| hb_filter (c->glyph_set, hb_first)
| hb_map (hb_second)
;
if (!it) return;
+ it
| hb_map (hb_add (this))
| hb_apply ([&] (const PairSet& _) { _.collect_variation_indices (c, valueFormat); })
;
}
void collect_glyphs (hb_collect_glyphs_context_t *c) const
{
if (unlikely (!(this+coverage).collect_coverage (c->input))) return;
unsigned int count = pairSet.len;
for (unsigned int i = 0; i < count; i++)
(this+pairSet[i]).collect_glyphs (c, valueFormat);
}
const Coverage &get_coverage () const { return this+coverage; }
struct external_cache_t
{
hb_ot_layout_mapping_cache_t coverage;
};
void *external_cache_create () const
{
external_cache_t *cache = (external_cache_t *) hb_malloc (sizeof (external_cache_t));
if (likely (cache))
{
cache->coverage.clear ();
}
return cache;
}
bool apply (hb_ot_apply_context_t *c, void *external_cache) const
{
TRACE_APPLY (this);
hb_buffer_t *buffer = c->buffer;
#ifndef HB_NO_OT_LAYOUT_LOOKUP_CACHE
external_cache_t *cache = (external_cache_t *) external_cache;
unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint, cache ? &cache->coverage : nullptr);
#else
unsigned int index = (this+coverage).get_coverage (buffer->cur().codepoint);
#endif
if (index == NOT_COVERED) return_trace (false);
auto &skippy_iter = c->iter_input;
skippy_iter.reset_fast (buffer->idx);
unsigned unsafe_to;
if (unlikely (!skippy_iter.next (&unsafe_to)))
{
buffer->unsafe_to_concat (buffer->idx, unsafe_to);
return_trace (false);
}
return_trace ((this+pairSet[index]).apply (c, valueFormat, skippy_iter.idx));
}
bool subset (hb_subset_context_t *c) const
{
TRACE_SUBSET (this);
const hb_set_t &glyphset = *c->plan->glyphset_gsub ();
const hb_map_t &glyph_map = *c->plan->glyph_map;
auto *out = c->serializer->start_embed (*this);
if (unlikely (!c->serializer->extend_min (out))) return_trace (false);
out->format = format;
hb_pair_t<unsigned, unsigned> newFormats = hb_pair (valueFormat[0], valueFormat[1]);
if (c->plan->normalized_coords)
{
/* all device flags will be dropped when full instancing, no need to strip
* hints, also do not strip emtpy cause we don't compute the new default
* value during stripping */
newFormats = compute_effective_value_formats (glyphset, false, false, &c->plan->layout_variation_idx_delta_map);
}
/* do not strip hints for VF */
else if (c->plan->flags & HB_SUBSET_FLAGS_NO_HINTING)
{
hb_blob_t* blob = hb_face_reference_table (c->plan->source, HB_TAG ('f','v','a','r'));
bool has_fvar = (blob != hb_blob_get_empty ());
hb_blob_destroy (blob);
bool strip = !has_fvar;
/* special case: strip hints when a VF has no GDEF varstore after
* subsetting*/
if (has_fvar && !c->plan->has_gdef_varstore)
strip = true;
newFormats = compute_effective_value_formats (glyphset, strip, true);
}
out->valueFormat[0] = newFormats.first;
out->valueFormat[1] = newFormats.second;
hb_sorted_vector_t<hb_codepoint_t> new_coverage;
+ hb_zip (this+coverage, pairSet)
| hb_filter (glyphset, hb_first)
| hb_filter ([this, c, out] (const typename Types::template OffsetTo<PairSet>& _)
{
auto snap = c->serializer->snapshot ();
auto *o = out->pairSet.serialize_append (c->serializer);
if (unlikely (!o)) return false;
bool ret = o->serialize_subset (c, _, this, valueFormat, out->valueFormat);
if (!ret)
{
out->pairSet.pop ();
c->serializer->revert (snap);
}
return ret;
},
hb_second)
| hb_map (hb_first)
| hb_map (glyph_map)
| hb_sink (new_coverage)
;
out->coverage.serialize_serialize (c->serializer, new_coverage.iter ());
return_trace (bool (new_coverage));
}
hb_pair_t<unsigned, unsigned> compute_effective_value_formats (const hb_set_t& glyphset,
bool strip_hints, bool strip_empty,
const hb_hashmap_t<unsigned, hb_pair_t<unsigned, int>> *varidx_delta_map = nullptr) const
{
unsigned record_size = PairSet::get_size (valueFormat);
unsigned format1 = 0;
unsigned format2 = 0;
for (const auto & _ :
+ hb_zip (this+coverage, pairSet)
| hb_filter (glyphset, hb_first)
| hb_map (hb_second)
)
{
const PairSet& set = (this + _);
const PairValueRecord *record = &set.firstPairValueRecord;
unsigned count = set.len;
for (unsigned i = 0; i < count; i++)
{
if (record->intersects (glyphset))
{
format1 = format1 | valueFormat[0].get_effective_format (record->get_values_1 (), strip_hints, strip_empty, &set, varidx_delta_map);
format2 = format2 | valueFormat[1].get_effective_format (record->get_values_2 (valueFormat[0]), strip_hints, strip_empty, &set, varidx_delta_map);
}
record = &StructAtOffset<const PairValueRecord> (record, record_size);
}
if (format1 == valueFormat[0] && format2 == valueFormat[1])
break;
}
return hb_pair (format1, format2);
}
};
}
}
}
#endif // OT_LAYOUT_GPOS_PAIRPOSFORMAT1_HH