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authorIndrajith K L2022-12-03 17:00:20 +0530
committerIndrajith K L2022-12-03 17:00:20 +0530
commitf5c4671bfbad96bf346bd7e9a21fc4317b4959df (patch)
tree2764fc62da58f2ba8da7ed341643fc359873142f /v_windows/v/vlib/encoding/base58/base58.v
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Adds most of the toolsHEADmaster
Diffstat (limited to 'v_windows/v/vlib/encoding/base58/base58.v')
-rw-r--r--v_windows/v/vlib/encoding/base58/base58.v181
1 files changed, 181 insertions, 0 deletions
diff --git a/v_windows/v/vlib/encoding/base58/base58.v b/v_windows/v/vlib/encoding/base58/base58.v
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+++ b/v_windows/v/vlib/encoding/base58/base58.v
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+// algorthim is adapted from https://github.com/mr-tron/base58 under the MIT license
+
+module base58
+
+import math
+
+// encode_int encodes any integer type to base58 string with Bitcoin alphabet
+pub fn encode_int(input int) ?string {
+ return encode_int_walpha(input, alphabets['btc'])
+}
+
+// encode_int_walpha any integer type to base58 string with custom alphabet
+pub fn encode_int_walpha(input int, alphabet Alphabet) ?string {
+ if input <= 0 {
+ return error(@MOD + '.' + @FN + ': input must be greater than zero')
+ }
+
+ mut buffer := []byte{}
+
+ mut i := input
+ for i > 0 {
+ remainder := i % 58
+ buffer << alphabet.encode[i8(remainder)]
+ // This needs to be casted so byte inputs can
+ // be used. i8 because remainder will never be
+ // over 58.
+ i = i / 58
+ }
+
+ return buffer.reverse().bytestr()
+}
+
+// encode encodes byte array to base58 with Bitcoin alphabet
+pub fn encode(input string) string {
+ return encode_walpha(input, alphabets['btc'])
+}
+
+// encode_walpha encodes byte array to base58 with custom aplhabet
+pub fn encode_walpha(input string, alphabet Alphabet) string {
+ if input.len == 0 {
+ return ''
+ }
+
+ bin := input.bytes()
+ mut sz := bin.len
+
+ mut zcount := 0
+ for zcount < sz && bin[zcount] == 0 {
+ zcount++
+ }
+
+ // It is crucial to make this as short as possible, especially for
+ // the usual case of Bitcoin addresses
+ sz = zcount + (sz - zcount) * 555 / 406 + 1
+ // integer simplification of
+ // ceil(log(256)/log(58))
+
+ mut out := []byte{len: sz}
+ mut i := 0
+ mut high := 0
+ mut carry := u32(0)
+
+ high = sz - 1
+ for b in bin {
+ i = sz - 1
+ for carry = u32(b); i > high || carry != 0; i-- {
+ carry = carry + 256 * u32(out[i])
+ out[i] = byte(carry % 58)
+ carry /= 58
+ }
+ high = 1
+ }
+
+ // determine additional "zero-gap" in the buffer, aside from zcount
+ for i = zcount; i < sz && out[i] == 0; i++ {}
+
+ // now encode the values with actual alphabet in-place
+ val := out[i - zcount..]
+ sz = val.len
+ for i = 0; i < sz; i++ {
+ out[i] = alphabet.encode[val[i]]
+ }
+
+ return out[..sz].bytestr()
+}
+
+// decode_int decodes base58 string to an integer with Bitcoin alphabet
+pub fn decode_int(input string) ?int {
+ return decode_int_walpha(input, alphabets['btc'])
+}
+
+// decode_int_walpha decodes base58 string to an integer with custom alphabet
+pub fn decode_int_walpha(input string, alphabet Alphabet) ?int {
+ mut total := 0 // to hold the results
+ b58 := input.reverse()
+ for i, ch in b58 {
+ ch_i := alphabet.encode.bytestr().index_byte(ch)
+ if ch_i == -1 {
+ return error(@MOD + '.' + @FN +
+ ': input string contains values not found in the provided alphabet')
+ }
+
+ val := ch_i * math.pow(58, i)
+
+ total += int(val)
+ }
+
+ return total
+}
+
+// decode decodes base58 string using the Bitcoin alphabet
+pub fn decode(str string) ?string {
+ return decode_walpha(str, alphabets['btc'])
+}
+
+// decode_walpha decodes base58 string using custom alphabet
+pub fn decode_walpha(str string, alphabet Alphabet) ?string {
+ if str.len == 0 {
+ return ''
+ }
+
+ zero := alphabet.encode[0]
+ b58sz := str.len
+
+ mut zcount := 0
+ for i := 0; i < b58sz && str[i] == zero; i++ {
+ zcount++
+ }
+
+ mut t := u64(0)
+ mut c := u64(0)
+
+ // the 32-bit algorithm stretches the result up to 2x
+ mut binu := []byte{len: 2 * ((b58sz * 406 / 555) + 1)}
+ mut outi := []u32{len: (b58sz + 3) / 4}
+
+ for _, r in str {
+ if r > 127 {
+ panic(@MOD + '.' + @FN +
+ ': high-bit set on invalid digit; outside of ascii range ($r). This should never happen.')
+ }
+ if alphabet.decode[r] == -1 {
+ return error(@MOD + '.' + @FN + ': invalid base58 digit ($r)')
+ }
+
+ c = u64(alphabet.decode[r])
+
+ for j := outi.len - 1; j >= 0; j-- {
+ t = u64(outi[j]) * 58 + c
+ c = t >> 32
+ outi[j] = u32(t & 0xffffffff)
+ }
+ }
+
+ // initial mask depend on b58sz, on further loops it always starts at 24 bits
+ mut mask := (u32(b58sz % 4) * 8)
+ if mask == 0 {
+ mask = 32
+ }
+ mask -= 8
+
+ mut out_len := 0
+ for j := 0; j < outi.len; j++ {
+ for mask < 32 {
+ binu[out_len] = byte(outi[j] >> mask)
+ mask -= 8
+ out_len++
+ }
+ mask = 24
+ }
+
+ // find the most significant byte post-decode, if any
+ for msb := zcount; msb < binu.len; msb++ { // loop relies on u32 overflow
+ if binu[msb] > 0 {
+ return binu[msb - zcount..out_len].bytestr()
+ }
+ }
+
+ // it's all zeroes
+ return binu[..out_len].bytestr()
+}