feature/esp_http_client: Added the esp_http_client component from idf.

Added the component and the example from IDF.

components/esp_http_client/lib/http_header.c

@@ -0,0 +1,239 @@
+// Copyright 2015-2018 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include "esp_log.h"
+#include "http_header.h"
+#include "http_utils.h"
+
+static const char *TAG = "HTTP_HEADER";
+#define HEADER_BUFFER (1024)
+
+/**
+ * dictionary item struct, with key-value pair
+ */
+typedef struct http_header_item {
+    char *key;                          /*!< key */
+    char *value;                        /*!< value */
+    STAILQ_ENTRY(http_header_item) next;   /*!< Point to next entry */
+} http_header_item_t;
+
+STAILQ_HEAD(http_header, http_header_item);
+
+
+http_header_handle_t http_header_init()
+{
+    http_header_handle_t header = calloc(1, sizeof(struct http_header));
+    HTTP_MEM_CHECK(TAG, header, return NULL);
+    STAILQ_INIT(header);
+    return header;
+}
+
+esp_err_t http_header_destroy(http_header_handle_t header)
+{
+    esp_err_t err = http_header_clean(header);
+    free(header);
+    return err;
+}
+
+http_header_item_handle_t http_header_get_item(http_header_handle_t header, const char *key)
+{
+    http_header_item_handle_t item;
+    if (header == NULL || key == NULL) {
+        return NULL;
+    }
+    STAILQ_FOREACH(item, header, next) {
+        if (strcasecmp(item->key, key) == 0) {
+            return item;
+        }
+    }
+    return NULL;
+}
+
+esp_err_t http_header_get(http_header_handle_t header, const char *key, char **value)
+{
+    http_header_item_handle_t item;
+
+    item = http_header_get_item(header, key);
+    if (item) {
+        *value = item->value;
+    } else {
+        *value = NULL;
+    }
+
+    return ESP_OK;
+}
+
+static esp_err_t http_header_new_item(http_header_handle_t header, const char *key, const char *value)
+{
+    http_header_item_handle_t item;
+
+    item = calloc(1, sizeof(http_header_item_t));
+    HTTP_MEM_CHECK(TAG, item, return ESP_ERR_NO_MEM);
+    http_utils_assign_string(&item->key, key, 0);
+    HTTP_MEM_CHECK(TAG, item->key, goto _header_new_item_exit);
+    http_utils_trim_whitespace(&item->key);
+    http_utils_assign_string(&item->value, value, 0);
+    HTTP_MEM_CHECK(TAG, item->value, goto _header_new_item_exit);
+    http_utils_trim_whitespace(&item->value);
+    STAILQ_INSERT_TAIL(header, item, next);
+    return ESP_OK;
+_header_new_item_exit:
+    free(item->key);
+    free(item->value);
+    return ESP_ERR_NO_MEM;
+}
+
+esp_err_t http_header_set(http_header_handle_t header, const char *key, const char *value)
+{
+    http_header_item_handle_t item;
+
+    if (value == NULL) {
+        return http_header_delete(header, key);
+    }
+
+    item = http_header_get_item(header, key);
+
+    if (item) {
+        free(item->value);
+        item->value = strdup(value);
+        http_utils_trim_whitespace(&item->value);
+        return ESP_OK;
+    }
+    return http_header_new_item(header, key, value);
+}
+
+esp_err_t http_header_set_from_string(http_header_handle_t header, const char *key_value_data)
+{
+    char *eq_ch;
+    char *p_str;
+
+    p_str = strdup(key_value_data);
+    HTTP_MEM_CHECK(TAG, p_str, return ESP_ERR_NO_MEM);
+    eq_ch = strchr(p_str, ':');
+    if (eq_ch == NULL) {
+        free(p_str);
+        return ESP_ERR_INVALID_ARG;
+    }
+    *eq_ch = 0;
+
+    http_header_set(header, p_str, eq_ch + 1);
+    free(p_str);
+    return ESP_OK;
+}
+
+
+esp_err_t http_header_delete(http_header_handle_t header, const char *key)
+{
+    http_header_item_handle_t item = http_header_get_item(header, key);
+    if (item) {
+        STAILQ_REMOVE(header, item, http_header_item, next);
+        free(item->key);
+        free(item->value);
+        free(item);
+    } else {
+        return ESP_ERR_NOT_FOUND;
+    }
+    return ESP_OK;
+}
+
+
+int http_header_set_format(http_header_handle_t header, const char *key, const char *format, ...)
+{
+    va_list argptr;
+    int len = 0;
+    char *buf = NULL;
+    va_start(argptr, format);
+    len = vasprintf(&buf, format, argptr);
+    HTTP_MEM_CHECK(TAG, buf, return 0);
+    va_end(argptr);
+    if (buf == NULL) {
+        return 0;
+    }
+    http_header_set(header, key, buf);
+    free(buf);
+    return len;
+}
+
+int http_header_generate_string(http_header_handle_t header, int index, char *buffer, int *buffer_len)
+{
+    http_header_item_handle_t item;
+    int siz = 0;
+    int idx = 0;
+    int ret_idx = -1;
+    bool is_end = false;
+    STAILQ_FOREACH(item, header, next) {
+        if (item->value && idx >= index) {
+            siz += strlen(item->key);
+            siz += strlen(item->value);
+            siz += 4; //': ' and '\r\n'
+        }
+        idx ++;
+
+        if (siz + 1 > *buffer_len - 2) {
+            ret_idx = idx - 1;
+        }
+    }
+
+    if (siz == 0) {
+        return 0;
+    }
+    if (ret_idx < 0) {
+        ret_idx = idx;
+        is_end = true;
+    }
+
+    int str_len = 0;
+    idx = 0;
+    STAILQ_FOREACH(item, header, next) {
+        if (item->value && idx >= index && idx < ret_idx) {
+            str_len += snprintf(buffer + str_len, *buffer_len - str_len, "%s: %s\r\n", item->key, item->value);
+        }
+        idx ++;
+    }
+    if (is_end) {
+        str_len += snprintf(buffer + str_len, *buffer_len - str_len, "\r\n");
+    }
+    *buffer_len = str_len;
+    return ret_idx;
+}
+
+esp_err_t http_header_clean(http_header_handle_t header)
+{
+    http_header_item_handle_t item = STAILQ_FIRST(header), tmp;
+    while (item != NULL) {
+        tmp = STAILQ_NEXT(item, next);
+        free(item->key);
+        free(item->value);
+        free(item);
+        item = tmp;
+    }
+    STAILQ_INIT(header);
+    return ESP_OK;
+}
+
+int http_header_count(http_header_handle_t header)
+{
+    http_header_item_handle_t item;
+    int count = 0;
+    STAILQ_FOREACH(item, header, next) {
+        count ++;
+    }
+    return count;
+}