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author | 2021-08-12 21:03:24 +0200 | |
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committer | 2021-08-12 21:03:24 +0200 | |
commit | 98263a7de64269898a2f81207e38943b5c8e8653 (patch) | |
tree | 743c90f109a6c5d27832d1dcef2388d939f0f77a /vendor/github.com/ugorji/go/codec/helper_internal.go | |
parent | Text duplication fix (#137) (diff) | |
download | gotosocial-98263a7de64269898a2f81207e38943b5c8e8653.tar.xz |
Grand test fixup (#138)
* start fixing up tests
* fix up tests + automate with drone
* fiddle with linting
* messing about with drone.yml
* some more fiddling
* hmmm
* add cache
* add vendor directory
* verbose
* ci updates
* update some little things
* update sig
Diffstat (limited to 'vendor/github.com/ugorji/go/codec/helper_internal.go')
-rw-r--r-- | vendor/github.com/ugorji/go/codec/helper_internal.go | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/vendor/github.com/ugorji/go/codec/helper_internal.go b/vendor/github.com/ugorji/go/codec/helper_internal.go new file mode 100644 index 000000000..e646249c7 --- /dev/null +++ b/vendor/github.com/ugorji/go/codec/helper_internal.go @@ -0,0 +1,147 @@ +// Copyright (c) 2012-2020 Ugorji Nwoke. All rights reserved. +// Use of this source code is governed by a MIT license found in the LICENSE file. + +package codec + +// maxArrayLen is the size of uint, which determines +// the maximum length of any array. +const maxArrayLen = 1<<((32<<(^uint(0)>>63))-1) - 1 + +// All non-std package dependencies live in this file, +// so porting to different environment is easy (just update functions). + +func pruneSignExt(v []byte, pos bool) (n int) { + if len(v) < 2 { + } else if pos && v[0] == 0 { + for ; v[n] == 0 && n+1 < len(v) && (v[n+1]&(1<<7) == 0); n++ { + } + } else if !pos && v[0] == 0xff { + for ; v[n] == 0xff && n+1 < len(v) && (v[n+1]&(1<<7) != 0); n++ { + } + } + return +} + +func halfFloatToFloatBits(h uint16) (f uint32) { + // retrofitted from: + // - OGRE (Object-Oriented Graphics Rendering Engine) + // function: halfToFloatI https://www.ogre3d.org/docs/api/1.9/_ogre_bitwise_8h_source.html + + s := uint32(h >> 15) + m := uint32(h & 0x03ff) + e := int32((h >> 10) & 0x1f) + + if e == 0 { + if m == 0 { // plus or minus 0 + return s << 31 + } + // Denormalized number -- renormalize it + for (m & 0x0400) == 0 { + m <<= 1 + e -= 1 + } + e += 1 + m &= ^uint32(0x0400) + } else if e == 31 { + if m == 0 { // Inf + return (s << 31) | 0x7f800000 + } + return (s << 31) | 0x7f800000 | (m << 13) // NaN + } + e = e + (127 - 15) + m = m << 13 + return (s << 31) | (uint32(e) << 23) | m +} + +func floatToHalfFloatBits(i uint32) (h uint16) { + // retrofitted from: + // - OGRE (Object-Oriented Graphics Rendering Engine) + // function: halfToFloatI https://www.ogre3d.org/docs/api/1.9/_ogre_bitwise_8h_source.html + // - http://www.java2s.com/example/java-utility-method/float-to/floattohalf-float-f-fae00.html + s := (i >> 16) & 0x8000 + e := int32(((i >> 23) & 0xff) - (127 - 15)) + m := i & 0x7fffff + + var h32 uint32 + + if e <= 0 { + if e < -10 { // zero + h32 = s // track -0 vs +0 + } else { + m = (m | 0x800000) >> uint32(1-e) + h32 = s | (m >> 13) + } + } else if e == 0xff-(127-15) { + if m == 0 { // Inf + h32 = s | 0x7c00 + } else { // NAN + m >>= 13 + var me uint32 + if m == 0 { + me = 1 + } + h32 = s | 0x7c00 | m | me + } + } else { + if e > 30 { // Overflow + h32 = s | 0x7c00 + } else { + h32 = s | (uint32(e) << 10) | (m >> 13) + } + } + h = uint16(h32) + return +} + +// growCap will return a new capacity for a slice, given the following: +// - oldCap: current capacity +// - unit: in-memory size of an element +// - num: number of elements to add +func growCap(oldCap, unit, num uint) (newCap uint) { + // appendslice logic (if cap < 1024, *2, else *1.25): + // leads to many copy calls, especially when copying bytes. + // bytes.Buffer model (2*cap + n): much better for bytes. + // smarter way is to take the byte-size of the appended element(type) into account + + // maintain 1 thresholds: + // t1: if cap <= t1, newcap = 2x + // else newcap = 1.5x + // + // t1 is always >= 1024. + // This means that, if unit size >= 16, then always do 2x or 1.5x (ie t1, t2, t3 are all same) + // + // With this, appending for bytes increase by: + // 100% up to 4K + // 50% beyond that + + // unit can be 0 e.g. for struct{}{}; handle that appropriately + maxCap := num + (oldCap * 3 / 2) + if unit == 0 || maxCap > maxArrayLen || maxCap < oldCap { // handle wraparound, etc + return maxArrayLen + } + + var t1 uint = 1024 // default thresholds for large values + if unit <= 4 { + t1 = 8 * 1024 + } else if unit <= 16 { + t1 = 2 * 1024 + } + + newCap = 2 + num + if oldCap > 0 { + if oldCap <= t1 { // [0,t1] + newCap = num + (oldCap * 2) + } else { // (t1,infinity] + newCap = maxCap + } + } + + // ensure newCap takes multiples of a cache line (size is a multiple of 64) + t1 = newCap * unit + if t2 := t1 % 64; t2 != 0 { + t1 += 64 - t2 + newCap = t1 / unit + } + + return +} |