热身赛一级赛题3

APP_Framework/Applications/app_test/Kconfig

@@ -240,5 +240,8 @@ menu "test app"
                 bool "Config test soft timer"
                 default n
             
+            menuconfig USER_TEST_HASH
+                bool "Config test hash table"
+                default n
         endif
 endmenu

APP_Framework/Applications/app_test/Makefile

@@ -99,6 +99,10 @@ ifeq ($(CONFIG_ADD_XIZI_FETURES),y)
 
     ifeq ($(CONFIG_USER_TEST_TIMER),y)
         SRC_FILES += test_timer.c
+    endif
+
+    ifeq ($(CONFIG_USER_TEST_HASH),y)
+        SRC_FILES += test_hash/test_hash.c
     endif    
 
     include $(KERNEL_ROOT)/compiler.mk

APP_Framework/Applications/app_test/test_hash/README.md

@@ -0,0 +1,74 @@
+# 哈希表
+
+## 1. 简介
+散列表（Hash table，也叫哈希表），是根据关键码值(Key value)而直接进行访问的数据结构。也就是说，它通过把关键码值映射到表中一个位置来访问记录，以加快查找的速度。这个映射函数叫做散列函数，存放记录的数组叫做散列表。
+
+## 2. 数据结构设计说明
+哈希表节点元素及哈希表设计如下：
+```
+typedef struct kv
+{
+    struct kv* next;
+    char* key;
+    void* value;
+}kv;
+
+/* HashTable */
+typedef struct HashTable
+{
+    struct kv ** table;
+}HashTable;
+```
+其中，一共实现了8个函数，分别为：
+- `init_kv`：构造一个哈希表节点并初始化
+- `free_kv`：删除一个哈希表节点
+- `hash_33`：经典Times33哈希函数
+- `hash_table_delete`：销毁一个哈希表
+- `hash_table_new`：构造一个哈希表并初始化
+- `hash_table_put2`：根据key插入或更新value
+- `hash_table_get`：根据key获取value
+- `hash_table_rm`：根据key移除一个键值对
+## 3. 测试程序说明
+测试程序 `TestHash` 已经注册为 shell 命令，可以调用执行。
+
+测试程序定义了以下键值对：
+```
+    char keys[][MAX_WORD_LEN] = {
+        "what",
+        "where",
+        "why",
+        "how",
+        "hello!",
+        "apple",
+        "12345"
+    };
+    int values[] = {1, 2, 3, 4, 5, 6, 7};
+```
+
+1.程序的第一部分创建了哈希表，并且将定义的 7 个键值对的前 6 个插入了基数树，然后分别查找 7 个键，前 6 个均可以找到对应的值，最后一个未插入，因此无法找到
+
+2.程序的第二部分从哈希表中删除了 where 和 how 两个键，再次分别查找 7 个键，删除的键值对和未插入的键值对均无法找到
+
+3.程序的第三部分重新插入了已删除的 where 和未插入过的 12345 ，再次分别查找 7 个键，新插入的值可以检索到
+
+4.程序的第四部分将哈希表销毁，再次分别查找 7 个键，所有的键值对均无法找到
+
+
+## 4. 运行结果（需结合运行测试截图按步骤说明）
+1.在工作区终端中输入命令，进入配置页面
+```
+cd /xiuos/Ubiquitous/XiZi_IIoT
+make BOARD=cortex-m3-emulator menuconfig
+```
+![fig1](1.png)
+2.依次进入 `APP_Framework` -> `Applications` -> `test app` 目录，将 `Enable application test function` 选项置为 `Y`
+![fig2](2.png)
+3.进入 `Enable application test function` 将 `Config test hash table` 选项置为 `Y`
+![fig3](3.png)
+4.一直选择 `Exit` 退出配置，在最后需要确认的页面选择 `Yes` 保存配置
+5.执行编译命令：`make BOARD=cortex-m3-emulator`，正常情况下应当编译无误
+![fig4](4.png)
+6.在 `qemu` 中运行：`qemu-system-arm -machine  lm3s6965evb -nographic -kernel build/XiZi-cortex-m3-emulator.elf`
+![fig5](5.png)
+7.在 shell 中运行命令 `TestHash`，执行结果与预期一致，验证完成。
+![fig6](6.png)

APP_Framework/Applications/app_test/test_hash/test_hash.c

@@ -0,0 +1,292 @@
+/**
+* @file:    test_hash.c
+* @brief:   Implement a simple hash
+* @version: 1.0
+* @date:    2023/5/29
+*/
+#include <transform.h>
+#include "test_hash.h"
+
+#define TABLE_SIZE 1024
+#define MAX_WORD_LEN 128
+
+
+/**
+ * @description: element of the hash table's chain list
+ * free_value is the destructor of value
+ */
+typedef struct kv
+{
+    struct kv* next;
+    char* key;
+    void* value;
+    // void(*free_value)(void*);
+}kv;
+
+/* HashTable */
+typedef struct HashTable
+{
+    struct kv ** table;
+}HashTable;
+
+/**
+ * @description: constructor of struct kv
+ * @param kv - element of the hash table's chain list
+ * @return void
+ */
+void init_kv(struct kv* kv)
+{
+    kv->next = NULL;
+    kv->key = NULL;
+    kv->value = NULL;
+    // kv->free_value = NULL;
+}
+
+/**
+ * @description: destructor of struct kv
+ * @param kv - element of the hash table's chain list
+ * @return void
+ */
+static void free_kv(struct kv* kv)
+{
+    if (kv) {
+        // if (kv->free_value) {
+        //     kv->free_value(kv->value);
+        // }
+        free(kv->key);
+        // free(kv->value);
+        kv->key = NULL;
+        free(kv);
+    }
+}
+
+/**
+ * @description: the classic Times33 hash function
+ * @param key - hash key
+ * @return unsigned int
+ */
+static unsigned int hash_33(char* key)
+{
+    unsigned int hash = 0;
+    while (*key) {
+        hash = (hash << 5) + hash + *key++;
+    }
+    return hash;
+}
+
+/**
+ * @description: delete a HashTable instance
+ * @param ht - HashTable*
+ * @return void
+ */
+void hash_table_delete(HashTable* ht)
+{
+    if (ht) {
+        if (ht->table) {
+            int i = 0;
+            for (i = 0; i<TABLE_SIZE&&ht->table[i]!=NULL; i++) {
+                struct kv* p = ht->table[i];
+                struct kv* q = NULL;
+                while (p) {
+                    q = p->next;
+                    free_kv(p);
+                    p = q;
+                }
+            }
+            free(ht->table);
+            ht->table = NULL;
+        }
+        free(ht);
+    }
+}
+
+
+/**
+ * @description: new a HashTable instance
+ * @return HashTable*
+ */
+HashTable* hash_table_new()
+{
+    HashTable* ht = malloc(sizeof(HashTable));
+    if (NULL == ht) {
+        hash_table_delete(ht);
+        return NULL;
+    }
+    ht->table = malloc(sizeof(struct kv*) * TABLE_SIZE);
+    if (NULL == ht->table) {
+        hash_table_delete(ht);
+        return NULL;
+    }
+    memset(ht->table, 0, sizeof(struct kv*) * TABLE_SIZE);
+
+    return ht;
+}
+
+
+/**
+ * @description: insert or update a value indexed by key
+ * @param ht - radix tree root
+ * @param key - new key
+ * @param value - new value
+ * @return int
+ */
+int hash_table_put2(HashTable* ht, char* key, void* value)
+{
+    int i = hash_33(key) % TABLE_SIZE;
+    struct kv* p = ht->table[i];
+    struct kv* prep = p;
+
+    while (p) { /* if key is already stroed, update its value */
+        if (strcmp(p->key, key) == 0) {
+            // free(p->value);
+            p->value = value;
+            break;
+        }
+        prep = p;
+        p = p->next;
+    }
+
+    if (p == NULL) {/* if key has not been stored, then add it */
+        char* kstr = malloc(strlen(key) + 1);
+        if (kstr == NULL) {
+            return -1;
+        }
+        struct kv * kv = malloc(sizeof(struct kv));
+        if (NULL == kv) {
+            free(kstr);
+            kstr = NULL;
+            return -1;
+        }
+        init_kv(kv);
+        kv->next = NULL;
+        strcpy(kstr, key);
+        kv->key = kstr;
+        kv->value = value;
+
+        if (prep == NULL) {
+            ht->table[i] = kv;
+        }
+        else {
+            prep->next = kv;
+        }
+    }
+    return 0;
+}
+
+/**
+ * @description: get a value indexed by key
+ * @param ht - radix tree root
+ * @param key - new key
+ * @return void* value
+ */
+void* hash_table_get(HashTable* ht, char* key)
+{
+    if(ht == NULL)return NULL;
+    int i = hash_33(key) % TABLE_SIZE;
+    struct kv* p = ht->table[i];
+    while (p) {
+        if (strcmp(key, p->key) == 0) {
+            return p->value;
+        }
+        p = p->next;
+    }
+    return NULL;
+}
+
+/**
+ * @description: remove a value indexed by key
+ * @param ht - radix tree root
+ * @param key - new key
+ * @return void
+ */
+void hash_table_rm(HashTable* ht, char* key)
+{
+    int i = hash_33(key) % TABLE_SIZE;
+
+    struct kv* p = ht->table[i];
+    struct kv* prep = p;
+    while (p) {
+        if (strcmp(key, p->key) == 0) {
+            free_kv(p);
+            if (p == prep) {
+                if(NULL==p->next)
+                    ht->table[i] = NULL;
+                else
+                    ht->table[i]=p->next;
+            }
+            else {
+                prep->next = p->next;
+            }
+            break;
+        }
+        prep = p;
+        p = p->next;
+    }
+}
+
+void TestHash()
+{
+    char keys[][MAX_WORD_LEN] = {
+        "what",
+        "where",
+        "why",
+        "how",
+        "hello!",
+        "apple",
+        "12345"
+    };
+    int values[] = {1, 2, 3, 4, 5, 6, 7};
+
+    printf("\nCreate hash table and add key & value:\n");
+    HashTable* ht = hash_table_new();
+    if (NULL == ht) {
+        printf("Create hash table failed.\n");
+        return;
+    }
+
+    // insert key&value into hash table
+    int num = sizeof(keys) / sizeof(keys[0]);
+    for (int i = 0; i < num - 1; ++i) {
+        hash_table_put2(ht, keys[i], &values[i]);
+    }
+
+    //find value by key
+    for (int i = 0; i < num; ++i) {
+        int* v = (int*)hash_table_get(ht, keys[i]);
+        if (v) printf("keys[%d] \"%s\"'v = %d, values[%d] = %d\n", i, keys[i], *v, i, values[i]);
+        else printf("keys[%d] \"%s\" not found\n", i, keys[i]);
+    }
+
+    printf("\nDelete \"where\" and \"how\":\n");
+    hash_table_rm(ht, keys[1]);
+    hash_table_rm(ht, keys[3]);
+    
+    for (int i = 0; i < num; ++i) {
+        int* v = (int*)hash_table_get(ht, keys[i]);
+        if (v) printf("keys[%d] \"%s\"'v = %d, values[%d] = %d\n", i, keys[i], *v, i, values[i]);
+        else printf("keys[%d] \"%s\" not found\n", i, keys[i]);
+    }
+
+    printf("\nInsert \"where\" and \"12345\":\n");
+    hash_table_put2(ht, keys[1], &values[1]);
+    hash_table_put2(ht, keys[6], &values[6]);
+
+    for (int i = 0; i < num; ++i) {
+        int* v = (int*)hash_table_get(ht, keys[i]);
+        if (v) printf("keys[%d] \"%s\"'v = %d, values[%d] = %d\n", i, keys[i], *v, i, values[i]);
+        else printf("keys[%d] \"%s\" not found\n", i, keys[i]);
+    }
+
+    printf("\nDestroy hash table:\n");
+    hash_table_delete(ht);
+    ht = NULL;
+
+    for (int i = 0; i < num; ++i) {
+        int* v = (int*)hash_table_get(ht, keys[i]);
+        if (v) printf("keys[%d] \"%s\"'v = %d, values[%d] = %d\n", i, keys[i], *v, i, values[i]);
+        else printf("keys[%d] \"%s\" not found\n", i, keys[i]);
+    }
+    return;
+}
+
+PRIV_SHELL_CMD_FUNCTION(TestHash, Implement a simple hash, PRIV_SHELL_CMD_MAIN_ATTR);

APP_Framework/Applications/app_test/test_hash/test_hash.h

@@ -0,0 +1,32 @@
+#pragma once
+typedef struct HashTable HashTable;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+    /* new an instance of HashTable */
+    HashTable* hash_table_new();
+
+    /*
+    delete an instance of HashTable,
+    all values are removed auotmatically.
+    */
+    void hash_table_delete(HashTable* ht);
+
+    /*
+    add or update a value to ht, 
+    free_value(if not NULL) is called automatically when the value is removed.
+    return 0 if success, -1 if error occurred.
+    */
+    int hash_table_put2(HashTable* ht, char* key, void* value);
+
+    /* get a value indexed by key, return NULL if not found. */
+    void* hash_table_get(HashTable* ht, char* key);
+
+    /* remove a value indexed by key */
+    void hash_table_rm(HashTable* ht, char* key);
+
+#ifdef __cplusplus
+}
+#endif