telebit/vendor/github.com/jcmturner/rpc/v2/ndr/arrays.go

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2020-06-03 06:18:04 +00:00
package ndr
import (
"errors"
"fmt"
"reflect"
"strconv"
)
// intFromTag returns an int that is a value in a struct tag key/value pair
func intFromTag(tag reflect.StructTag, key string) (int, error) {
ndrTag := parseTags(tag)
d := 1
if n, ok := ndrTag.Map[key]; ok {
i, err := strconv.Atoi(n)
if err != nil {
return d, fmt.Errorf("invalid dimensions tag [%s]: %v", n, err)
}
d = i
}
return d, nil
}
// parseDimensions returns the a slice of the size of each dimension and type of the member at the deepest level.
func parseDimensions(v reflect.Value) (l []int, tb reflect.Type) {
if v.Kind() == reflect.Ptr {
v = v.Elem()
}
t := v.Type()
if t.Kind() == reflect.Ptr {
t = t.Elem()
}
if t.Kind() != reflect.Array && t.Kind() != reflect.Slice {
return
}
l = append(l, v.Len())
if t.Elem().Kind() == reflect.Array || t.Elem().Kind() == reflect.Slice {
// contains array or slice
var m []int
m, tb = parseDimensions(v.Index(0))
l = append(l, m...)
} else {
tb = t.Elem()
}
return
}
// sliceDimensions returns the count of dimensions a slice has.
func sliceDimensions(t reflect.Type) (d int, tb reflect.Type) {
if t.Kind() == reflect.Ptr {
t = t.Elem()
}
if t.Kind() == reflect.Slice {
d++
var n int
n, tb = sliceDimensions(t.Elem())
d += n
} else {
tb = t
}
return
}
// makeSubSlices is a deep recursive creation/initialisation of multi-dimensional slices.
// Takes the reflect.Value of the 1st dimension and a slice of the lengths of the sub dimensions
func makeSubSlices(v reflect.Value, l []int) {
ty := v.Type().Elem()
if ty.Kind() != reflect.Slice {
return
}
for i := 0; i < v.Len(); i++ {
s := reflect.MakeSlice(ty, l[0], l[0])
v.Index(i).Set(s)
// Are there more sub dimensions?
if len(l) > 1 {
makeSubSlices(v.Index(i), l[1:])
}
}
return
}
// multiDimensionalIndexPermutations returns all the permutations of the indexes of a multi-dimensional slice.
// The input is a slice of integers that indicates the max size/length of each dimension
func multiDimensionalIndexPermutations(l []int) (ps [][]int) {
z := make([]int, len(l), len(l)) // The zeros permutation
ps = append(ps, z)
// for each dimension, in reverse
for i := len(l) - 1; i >= 0; i-- {
ws := make([][]int, len(ps))
copy(ws, ps)
//create a permutation for each of the iterations of the current dimension
for j := 1; j <= l[i]-1; j++ {
// For each existing permutation
for _, p := range ws {
np := make([]int, len(p), len(p))
copy(np, p)
np[i] = j
ps = append(ps, np)
}
}
}
return
}
// precedingMax reads off the next conformant max value
func (dec *Decoder) precedingMax() uint32 {
m := dec.conformantMax[0]
dec.conformantMax = dec.conformantMax[1:]
return m
}
// fillFixedArray establishes if the fixed array is uni or multi dimensional and then fills it.
func (dec *Decoder) fillFixedArray(v reflect.Value, tag reflect.StructTag, def *[]deferedPtr) error {
l, t := parseDimensions(v)
if t.Kind() == reflect.String {
tag = reflect.StructTag(subStringArrayTag)
}
if len(l) < 1 {
return errors.New("could not establish dimensions of fixed array")
}
if len(l) == 1 {
err := dec.fillUniDimensionalFixedArray(v, tag, def)
if err != nil {
return fmt.Errorf("could not fill uni-dimensional fixed array: %v", err)
}
return nil
}
// Fixed array is multidimensional
ps := multiDimensionalIndexPermutations(l[:len(l)-1])
for _, p := range ps {
// Get current multi-dimensional index to fill
a := v
for _, i := range p {
a = a.Index(i)
}
// fill with the last dimension array
err := dec.fillUniDimensionalFixedArray(a, tag, def)
if err != nil {
return fmt.Errorf("could not fill dimension %v of multi-dimensional fixed array: %v", p, err)
}
}
return nil
}
// readUniDimensionalFixedArray reads an array (not slice) from the byte stream.
func (dec *Decoder) fillUniDimensionalFixedArray(v reflect.Value, tag reflect.StructTag, def *[]deferedPtr) error {
for i := 0; i < v.Len(); i++ {
err := dec.fill(v.Index(i), tag, def)
if err != nil {
return fmt.Errorf("could not fill index %d of fixed array: %v", i, err)
}
}
return nil
}
// fillConformantArray establishes if the conformant array is uni or multi dimensional and then fills the slice.
func (dec *Decoder) fillConformantArray(v reflect.Value, tag reflect.StructTag, def *[]deferedPtr) error {
d, _ := sliceDimensions(v.Type())
if d > 1 {
err := dec.fillMultiDimensionalConformantArray(v, d, tag, def)
if err != nil {
return err
}
} else {
err := dec.fillUniDimensionalConformantArray(v, tag, def)
if err != nil {
return err
}
}
return nil
}
// fillUniDimensionalConformantArray fills the uni-dimensional slice value.
func (dec *Decoder) fillUniDimensionalConformantArray(v reflect.Value, tag reflect.StructTag, def *[]deferedPtr) error {
m := dec.precedingMax()
n := int(m)
a := reflect.MakeSlice(v.Type(), n, n)
for i := 0; i < n; i++ {
err := dec.fill(a.Index(i), tag, def)
if err != nil {
return fmt.Errorf("could not fill index %d of uni-dimensional conformant array: %v", i, err)
}
}
v.Set(a)
return nil
}
// fillMultiDimensionalConformantArray fills the multi-dimensional slice value provided from conformant array data.
// The number of dimensions must be specified. This must be less than or equal to the dimensions in the slice for this
// method not to panic.
func (dec *Decoder) fillMultiDimensionalConformantArray(v reflect.Value, d int, tag reflect.StructTag, def *[]deferedPtr) error {
// Read the max size of each dimensions from the ndr stream
l := make([]int, d, d)
for i := range l {
l[i] = int(dec.precedingMax())
}
// Initialise size of slices
// Initialise the size of the 1st dimension
ty := v.Type()
v.Set(reflect.MakeSlice(ty, l[0], l[0]))
// Initialise the size of the other dimensions recursively
makeSubSlices(v, l[1:])
// Get all permutations of the indexes and go through each and fill
ps := multiDimensionalIndexPermutations(l)
for _, p := range ps {
// Get current multi-dimensional index to fill
a := v
for _, i := range p {
a = a.Index(i)
}
err := dec.fill(a, tag, def)
if err != nil {
return fmt.Errorf("could not fill index %v of slice: %v", p, err)
}
}
return nil
}
// fillVaryingArray establishes if the varying array is uni or multi dimensional and then fills the slice.
func (dec *Decoder) fillVaryingArray(v reflect.Value, tag reflect.StructTag, def *[]deferedPtr) error {
d, t := sliceDimensions(v.Type())
if d > 1 {
err := dec.fillMultiDimensionalVaryingArray(v, t, d, tag, def)
if err != nil {
return err
}
} else {
err := dec.fillUniDimensionalVaryingArray(v, tag, def)
if err != nil {
return err
}
}
return nil
}
// fillUniDimensionalVaryingArray fills the uni-dimensional slice value.
func (dec *Decoder) fillUniDimensionalVaryingArray(v reflect.Value, tag reflect.StructTag, def *[]deferedPtr) error {
o, err := dec.readUint32()
if err != nil {
return fmt.Errorf("could not read offset of uni-dimensional varying array: %v", err)
}
s, err := dec.readUint32()
if err != nil {
return fmt.Errorf("could not establish actual count of uni-dimensional varying array: %v", err)
}
t := v.Type()
// Total size of the array is the offset in the index being passed plus the actual count of elements being passed.
n := int(s + o)
a := reflect.MakeSlice(t, n, n)
// Populate the array starting at the offset specified
for i := int(o); i < n; i++ {
err := dec.fill(a.Index(i), tag, def)
if err != nil {
return fmt.Errorf("could not fill index %d of uni-dimensional varying array: %v", i, err)
}
}
v.Set(a)
return nil
}
// fillMultiDimensionalVaryingArray fills the multi-dimensional slice value provided from varying array data.
// The number of dimensions must be specified. This must be less than or equal to the dimensions in the slice for this
// method not to panic.
func (dec *Decoder) fillMultiDimensionalVaryingArray(v reflect.Value, t reflect.Type, d int, tag reflect.StructTag, def *[]deferedPtr) error {
// Read the offset and actual count of each dimensions from the ndr stream
o := make([]int, d, d)
l := make([]int, d, d)
for i := range l {
off, err := dec.readUint32()
if err != nil {
return fmt.Errorf("could not read offset of dimension %d: %v", i+1, err)
}
o[i] = int(off)
s, err := dec.readUint32()
if err != nil {
return fmt.Errorf("could not read size of dimension %d: %v", i+1, err)
}
l[i] = int(s) + int(off)
}
// Initialise size of slices
// Initialise the size of the 1st dimension
ty := v.Type()
v.Set(reflect.MakeSlice(ty, l[0], l[0]))
// Initialise the size of the other dimensions recursively
makeSubSlices(v, l[1:])
// Get all permutations of the indexes and go through each and fill
ps := multiDimensionalIndexPermutations(l)
for _, p := range ps {
// Get current multi-dimensional index to fill
a := v
var os bool // should this permutation be skipped due to the offset of any of the dimensions?
for i, j := range p {
if j < o[i] {
os = true
break
}
a = a.Index(j)
}
if os {
// This permutation should be skipped as it is less than the offset for one of the dimensions.
continue
}
err := dec.fill(a, tag, def)
if err != nil {
return fmt.Errorf("could not fill index %v of slice: %v", p, err)
}
}
return nil
}
// fillConformantVaryingArray establishes if the varying array is uni or multi dimensional and then fills the slice.
func (dec *Decoder) fillConformantVaryingArray(v reflect.Value, tag reflect.StructTag, def *[]deferedPtr) error {
d, t := sliceDimensions(v.Type())
if d > 1 {
err := dec.fillMultiDimensionalConformantVaryingArray(v, t, d, tag, def)
if err != nil {
return err
}
} else {
err := dec.fillUniDimensionalConformantVaryingArray(v, tag, def)
if err != nil {
return err
}
}
return nil
}
// fillUniDimensionalConformantVaryingArray fills the uni-dimensional slice value.
func (dec *Decoder) fillUniDimensionalConformantVaryingArray(v reflect.Value, tag reflect.StructTag, def *[]deferedPtr) error {
m := dec.precedingMax()
o, err := dec.readUint32()
if err != nil {
return fmt.Errorf("could not read offset of uni-dimensional conformant varying array: %v", err)
}
s, err := dec.readUint32()
if err != nil {
return fmt.Errorf("could not establish actual count of uni-dimensional conformant varying array: %v", err)
}
if m < o+s {
return errors.New("max count is less than the offset plus actual count")
}
t := v.Type()
n := int(s)
a := reflect.MakeSlice(t, n, n)
for i := int(o); i < n; i++ {
err := dec.fill(a.Index(i), tag, def)
if err != nil {
return fmt.Errorf("could not fill index %d of uni-dimensional conformant varying array: %v", i, err)
}
}
v.Set(a)
return nil
}
// fillMultiDimensionalConformantVaryingArray fills the multi-dimensional slice value provided from conformant varying array data.
// The number of dimensions must be specified. This must be less than or equal to the dimensions in the slice for this
// method not to panic.
func (dec *Decoder) fillMultiDimensionalConformantVaryingArray(v reflect.Value, t reflect.Type, d int, tag reflect.StructTag, def *[]deferedPtr) error {
// Read the offset and actual count of each dimensions from the ndr stream
m := make([]int, d, d)
for i := range m {
m[i] = int(dec.precedingMax())
}
o := make([]int, d, d)
l := make([]int, d, d)
for i := range l {
off, err := dec.readUint32()
if err != nil {
return fmt.Errorf("could not read offset of dimension %d: %v", i+1, err)
}
o[i] = int(off)
s, err := dec.readUint32()
if err != nil {
return fmt.Errorf("could not read actual count of dimension %d: %v", i+1, err)
}
if m[i] < int(s)+int(off) {
m[i] = int(s) + int(off)
}
l[i] = int(s)
}
// Initialise size of slices
// Initialise the size of the 1st dimension
ty := v.Type()
v.Set(reflect.MakeSlice(ty, m[0], m[0]))
// Initialise the size of the other dimensions recursively
makeSubSlices(v, m[1:])
// Get all permutations of the indexes and go through each and fill
ps := multiDimensionalIndexPermutations(m)
for _, p := range ps {
// Get current multi-dimensional index to fill
a := v
var os bool // should this permutation be skipped due to the offset of any of the dimensions or max is higher than the actual count being passed
for i, j := range p {
if j < o[i] || j >= l[i] {
os = true
break
}
a = a.Index(j)
}
if os {
// This permutation should be skipped as it is less than the offset for one of the dimensions.
continue
}
err := dec.fill(a, tag, def)
if err != nil {
return fmt.Errorf("could not fill index %v of slice: %v", p, err)
}
}
return nil
}