/*
 * 基本处理
 * 肖俊
 * 2015-4-2
 */

using System.Text;

namespace AllBase
{
    public static class BaseWork
    {
        /// <summary>
        /// 两个数组是否相同
        /// </summary>
        /// <param name="b1"></param>
        /// <param name="b2"></param>
        /// <returns></returns>
        public static bool IsSame(ref byte[] b1, ref byte[] b2)
        {
            if (b1.Length != b2.Length)
                return false;
            for (int i = 0; i < b1.Length; i++)
                if (b1[i] != b2[i])
                    return false;
            return true;
        }
        /// <summary>
        /// 取得一个数组在另一个数组中的位置
        /// </summary>
        /// <param name="b1">主数组</param>
        /// <param name="b2">查找数组</param>
        /// <param name="start">起点</param>
        /// <returns></returns>
        public static int GetIndexFirst(ref byte[] b1, ref byte[] b2, int start)
        {
            if (b1.Length < b2.Length || start > b1.Length - 1)
                return -1;
            int j;
            for (int i = start; i < b1.Length - b2.Length+1; i++)
            {
                if (b1[i] != b2[0])
                    continue;
                for (j = 1; j < b2.Length; j++)
                    if (b1[i + j] != b2[j])
                        break;
                if (j == b2.Length)
                    return i;
            }
            return -1;
        }
        /// <summary>
        /// 一个数组是否在另一个数组的结尾
        /// </summary>
        /// <param name="getByte">主数据</param>
        /// <param name="end">结尾数组</param>
        /// <returns></returns>
        public static bool IsEndByte(ref byte[] getByte, ref byte[] end)
        {
            if (end.Length > getByte.Length)
                return false;
            int i, c = getByte.Length - end.Length;
            for (i = 0; i < end.Length; i++)
                if (end[i] != getByte[c + i])
                    break;
            if (i == end.Length)
                return true;
            return false;
        }

        /// <summary>
        /// 取得一个数组在另一个数组中的位置
        /// </summary>
        /// <param name="b1">主数组</param>
        /// <param name="b2">查找数组</param>
        /// <returns></returns>
        public static int GetIndexLast(ref byte[] b1, ref byte[] b2)
        {
            if (b1.Length < b2.Length)
                return -1;
            int j, end = b2.Length - 1;
            for (int i = b1.Length - 1; i >= end; i--)
            {
                if (b1[i] != b2[end])
                    continue;
                for (j = 1; j < b2.Length; j++)
                    if (b1[i - j] != b2[end - j])
                        break;
                if (j == b2.Length)
                    return i - end;
            }
            return -1;
        }
    }
}