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authorLibravatar Tobi Smethurst <31960611+tsmethurst@users.noreply.github.com>2021-08-12 21:03:24 +0200
committerLibravatar GitHub <noreply@github.com>2021-08-12 21:03:24 +0200
commit98263a7de64269898a2f81207e38943b5c8e8653 (patch)
tree743c90f109a6c5d27832d1dcef2388d939f0f77a /vendor/github.com/ugorji/go/codec/helper_internal.go
parentText duplication fix (#137) (diff)
downloadgotosocial-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.go147
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
+}