红色珠子，开启Redis系列之旅（redis珠子系列）

红色珠子，开启Redis系列之旅

Redis是一个内存数据存储系统，设计简单，性能强大，丰富的数据结构和高效的操作使得Redis可以应用于各种场景，包括缓存，队列等等。而作为新手，一种直观的学习方式便是通过代码实战。在此，我们将从实现一个简单的红色珠子游戏开始我们的Redis之旅。

红色珠子是一个小型休闲游戏，游戏规则十分简单，通过操作珠子的位置，将同色连成一线。而以文章长度来看，简单版红色珠子（也称作六角珠子）已经足够，我们来看下游戏界面。

![image.png](https://cdn.nlark.com/yuque/0/2022/png/197765/1645352734622-db3122d5-1bed-4172-8ce5-5bd04cf5b908.png#clientId=ue0d39fe3-d1d4-4&from=paste&height=310&id=ud97fd4b4&margin=%5Bobject%20Object%5D&name=image.png&originHeight=620&originWidth=648&originalType=binary&ratio=1&size=70820&status=done&style=none&taskId=uc8a0c1de-224b-4e2e-a4cf-73980ead7b4&width=324)

我们需要在Redis中存储一份游戏数据，我们定义一个代表整个游戏区域的键值，其值为一个列表。列表中各元素的值表示当前位置珠子的种类编号，还需要维护其他元数据，例如步数。

“`python

import redis

# Redis 实例

r = redis.StrictRedis(host=’localhost’, port=6379, db=0)

# 游戏区域，这里我们简单起见使用一个固定大小的 7×7 区域，61 代表无珠子

GAME_KEY = “hexagon”

GAME_WIDTH = 7

GAME_HEIGHT = 7

GAME_SIZE = GAME_WIDTH * GAME_HEIGHT

GAME_BALL_NUM = 7

BALL_NONE = 0

BALL_RED = 1

BALL_ORANGE = 2

BALL_YELLOW = 3

BALL_GREEN = 4

BALL_CYAN = 5

BALL_BLUE = 6

BALL_PURPLE = 7

BALL_REMOVE_FLAG = 100

def init_game():

“””

初始化游戏区域

“””

# 随机填充球

balls = [random_ball() for _ in range(GAME_SIZE)]

r.delete(GAME_KEY)

r.rpush(GAME_KEY, *balls)

# 初始化其他元数据

r.set(GAME_KEY + “_step”, 0)

def print_game():

“””

输出当前游戏状态

“””

# 读取游戏区域数据

balls = r.lrange(GAME_KEY, 0, GAME_SIZE – 1)

# 构造游戏区域表格

lines = []

for j in range(GAME_HEIGHT):

indent = “” if j % 2 == 0 else ” “

line = ” ” * j + indent

for i in range(GAME_WIDTH):

idx = j * GAME_WIDTH + i

ball = int(balls[idx])

line += ” ” if ball == BALL_NONE else “{:02d}”.format(ball)

lines.append(line)

# 输出表格

print(“-” * (GAME_WIDTH * 3 + 2))

for line in lines:

print(“| ” + line + ” |”)

print(“-” * (GAME_WIDTH * 3 + 2))

# 输出其他元数据

print(“Step: {}”.format(r.get(GAME_KEY + “_step”)))


根据以上代码，我们实现了初始化游戏区域和输出游戏状态两个功能。其中重点在于 init_game() 函数，这里我们随机生成一定数量的珠子填充游戏区域，从视觉效果上更接近玩家的预期，同时由于 Redis 实例得以支持多客户端，类似于调用 r.delete() 可以代替 redis-cli 中的 flushdb 清空所有数据。

随后，我们便需要实现“将同色连成一线”这一功能，游戏规则十分简单，只需要同行和同列都满足相同颜色，即将这些珠子消除，得分并移动高处的珠子填空。反复执行此操作直到无法消除为止。

```python
from collections import deque
def print_usage():
    """
    输出操作指南
    """
    print("""
    q: 退出游戏
    ,: 选择一个位置，标记为要消除的珠子
    """)

def mark_ball(x, y):
    """
    标记要消除的珠子
    """
    balls = r.lrange(GAME_KEY, 0, GAME_SIZE - 1)
    idx = y * GAME_WIDTH + x
    ball = int(balls[idx])
    if ball == BALL_NONE:
        return False
    replace_ball = BALL_REMOVE_FLAG if ball != BALL_REMOVE_FLAG else BALL_NONE
    r.lset(GAME_KEY, idx, replace_ball)
    return True
def bfs(balls, start_idx):
    """
    广度优先搜索查找相邻珠子
    """
    colors = [int(balls[start_idx])]
    queue = deque([start_idx])
    visited = set([start_idx])
    while queue:
        idx = queue.popleft()
        x, y = idx % GAME_WIDTH, idx // GAME_WIDTH
        for dx, dy in ((-1, 0), (1, 0), (-1, -1), (1, -1), (0, 1), (0, -1)):
            new_x, new_y = x + dx, y + dy
            if new_x = GAME_WIDTH or new_y = GAME_HEIGHT:
                continue
            new_idx = new_y * GAME_WIDTH + new_x
            if new_idx in visited:
                continue
            if int(balls[new_idx]) == int(balls[start_idx]):
                colors.append(int(balls[new_idx]))
                queue.append(new_idx)
                visited.add(new_idx)
    return colors, visited
def find_groups(balls):
    """
    查找所有可消除的珠子
    """
    groups = []
    visited = set()
    for idx in range(GAME_SIZE):
        ball = int(balls[idx])
        if ball == BALL_NONE or idx in visited:
            continue
        colors, region = bfs(balls, idx)
        if len(colors) >= 3:
            groups.append(region)
        visited |= region
    return groups

def delete_groups():
    """
    删除所有可消除的珠子
    """
    balls = r.lrange(GAME_KEY, 0, GAME_SIZE - 1)
    groups = find_groups(balls)
    if not groups:
        return False
    # 打印并更新信息
    print("Group count: {}, balls count: {}".format(len(groups), sum([len(g) for g in groups])))
    r.incrby(GAME_KEY + "_step", len(groups))
    # 依次更新珠子位置
    for group in groups:
        for idx in sorted(group, reverse=True):
            r.lset(GAME_KEY, idx, BALL_NONE)
        top_indexes = [idx - GAME_WIDTH for idx in sorted(group) if idx >= GAME_WIDTH]
        for idx in top_indexes:
            offset = 0
            while idx - offset >= 0:
                if int(balls[idx - offset]) != BALL_NONE:
                    r.lset(GAME_KEY, idx - offset + GAME_WIDTH, balls[idx - offset])
                offset += 1
            r.lset(GAME_KEY, idx - offset + GAME_WIDTH, BALL_NONE)
    return True
init_game()
print_game()
while True:
    print_usage()
    cmd = input("> ")
    if cmd == "q":
        break
    try:
        x, y = [int(i.strip()) for i in cmd.split(",")]
    except Exception as e:
        print("Invalid input format")
        continue
    if x = GAME_WIDTH or y = GAME_HEIGHT:
        print("Out of range")
        continue
    if not mark_ball(x, y):
        print("No ball in that position")
        continue
    while delete_groups():
        print_game()