crypto.rand: fix linux/solaris rand.read() compilation

vlib/crypto/rand/rand_linux.c.v

@@ -1,34 +1,34 @@
 // Copyright (c) 2019-2020 Alexander Medvednikov. All rights reserved.
 // Use of this source code is governed by an MIT license
 // that can be found in the LICENSE file.
-
 module rand
 
-import math
-
 #include <sys/syscall.h>
-
 const (
 	read_batch_size = 256
 )
 
-pub fn read(bytes_needed int) ?[]byte {	
-	buffer := malloc(bytes_needed)
+pub fn read(bytes_needed int) ?[]byte {
+	mut buffer := &byte(0)
+	unsafe {
+		buffer = malloc(bytes_needed)
+	}
+	mut bstart := buffer
 	mut bytes_read := 0
+	mut remaining_bytes := bytes_needed
 	// getrandom syscall wont block if requesting <= 256 bytes
-	if bytes_needed > read_batch_size {
-		no_batches := int(math.floor(f64(bytes_needed/read_batch_size)))
-		for i:=0; i < no_batches; i++ {
-			if getrandom(read_batch_size, buffer+bytes_read) == -1 {
-				return read_error
-			}
-			bytes_read += read_batch_size
+	for bytes_read < bytes_needed {
+		batch_size := if remaining_bytes > read_batch_size { read_batch_size } else { remaining_bytes }
+		unsafe {
+			bstart = buffer + bytes_read
 		}
+		rbytes := getrandom(batch_size, bstart)
+		if rbytes == -1 {
+			free(buffer)
+			return read_error
+		}
+		bytes_read += rbytes
 	}
-	if getrandom(bytes_needed-bytes_read, buffer+bytes_read) == -1 {
-		return read_error
-	}
-	
 	return c_array_to_bytes_tmp(bytes_needed, buffer)
 }
 

vlib/crypto/rand/rand_solaris.c.v

@@ -4,8 +4,6 @@
 
 module rand
 
-import math
-
 #include <sys/random.h>
 
 fn C.getrandom(p byteptr, n size_t, flags u32) int
@@ -14,26 +12,27 @@ const (
 	read_batch_size = 256
 )
 
-pub fn read(bytes_needed int) ?[]byte {	
+pub fn read(bytes_needed int) ?[]byte {
 	mut buffer := &byte(0)
 	unsafe {
-	   buffer = malloc(bytes_needed)
+		buffer = malloc(bytes_needed)
 	}
+	mut bstart := buffer
 	mut bytes_read := 0
+	mut remaining_bytes := bytes_needed
 	// getrandom syscall wont block if requesting <= 256 bytes
-	if bytes_needed > read_batch_size {
-		no_batches := int(math.floor(f64(bytes_needed/read_batch_size)))
-		for i:=0; i<no_batches; i++ {
-			if v_getrandom(read_batch_size, buffer+bytes_read) == -1 {
-				return read_error
-			}
-			bytes_read += read_batch_size
+	for bytes_read < bytes_needed {
+		batch_size := if remaining_bytes > read_batch_size { read_batch_size } else { remaining_bytes }
+		unsafe {
+			bstart = buffer + bytes_read
 		}
+		rbytes := getrandom(batch_size, bstart)
+		if rbytes == -1 {
+			free(buffer)
+			return read_error
+		}
+		bytes_read += rbytes
 	}
-	if v_getrandom(bytes_needed-bytes_read, buffer+bytes_read) == -1 {
-		return read_error
-	}
-	
 	return c_array_to_bytes_tmp(bytes_needed, buffer)
 }