|
| 1 | +--- |
| 2 | +catalog: true |
| 3 | +title: '分片上传' |
| 4 | +sidebar: |
| 5 | + nav: c-sdk |
| 6 | + |
| 7 | +--- |
| 8 | + |
| 9 | + |
| 10 | + |
| 11 | +本 SDK 提供了分片上传（Multipart Upload）功能，可以将要上传的文件分成多个数据块（US3 里又称之为 Part）来分别上传，适用于大文件。 |
| 12 | + |
| 13 | +## 分片上传流程 |
| 14 | + |
| 15 | +在US3中，一个完整的分片上传分为**初始化分片 -> 上传分片 -> 完成分片(放弃分片)**三个阶段。本SDK提供的相应方法如下，完整代码详见 [Github](https://github.com/ufilesdk-dev/ufile-csdk/blob/master/lib/ufile_mput.c) |
| 16 | + |
| 17 | +| 方法名 | 说明 | |
| 18 | +| :--------------------------- | :----------------------------------------------------------- | |
| 19 | +| ufile_multiple_upload_init | 初始化分片上传，US3 API 文档详见 [InitiateMultipartUpload](https://docs.ucloud.cn/api/ufile-api/initiate_multipart_upload) | |
| 20 | +| ufile_multiple_upload_part | 上传一个分片，US3 API 文档详见 [UploadPart](https://docs.ucloud.cn/api/ufile-api/upload_part) | |
| 21 | +| ufile_multiple_upload_finish | 终止分片上传，US3 API 文档详见 [AbortMultipartUpload](https://docs.ucloud.cn/api/ufile-api/abort_multipart_upload) | |
| 22 | +| ufile_multiple_upload_abort | 完成分片上传，US3 API 文档详见 [FinishMultipartUpload](https://docs.ucloud.cn/api/ufile-api/finish_multipart_upload) | |
| 23 | + |
| 24 | +目前SDK提供同步分片上传和异步并发分片上传两种方式，示例如下。 |
| 25 | + |
| 26 | +## 同步分片上传 |
| 27 | + |
| 28 | +注意，当前SDK并未直接提供同步分片上传方法供外部调用，若使用同步分片上传请参照示例实现。如有疑问，可到[Github](https://github.com/ufilesdk-dev/ufile-csdk/issues)上提交issue或[联系我们](https://spt.ucloud.cn/)； |
| 29 | + |
| 30 | +### 示例 |
| 31 | + |
| 32 | +> 执行该示例请先配置`UFILE_*`相关环境变量并赋予`bucket_name`、`key`、`mime_type`和`file_path`有效值。 |
| 33 | +
|
| 34 | +<div class="copyable" markdown="1"> |
| 35 | + |
| 36 | +```c |
| 37 | +#include "../lib/api.h" |
| 38 | +#include <stdio.h> |
| 39 | +#include <stdlib.h> |
| 40 | + |
| 41 | +const char* bucket_name = "your bucket name"; |
| 42 | +const char* key = "your file key"; |
| 43 | +const char* file_path = "your local file to be uploaded"; |
| 44 | +const char* mime_type = "your file type"; |
| 45 | + |
| 46 | +int main(int argc, char *argv[]){ |
| 47 | + // 读取配置初始化SDK |
| 48 | + struct ufile_config cfg; |
| 49 | + cfg.public_key = getenv("UFILE_PUBLIC_KEY"); |
| 50 | + cfg.private_key = getenv("UFILE_PRIVATE_KEY"); |
| 51 | + cfg.bucket_host = getenv("UFILE_BUCKET_HOST"); |
| 52 | + cfg.file_host = getenv("UFILE_FILE_HOST"); |
| 53 | + struct ufile_error error; |
| 54 | + error = ufile_sdk_initialize(cfg, 0); |
| 55 | + if(UFILE_HAS_ERROR(error.code)){ |
| 56 | + printf("初始化 sdk 失败，错误信息为：%s\n", error.message); |
| 57 | + return 1; |
| 58 | + } |
| 59 | + |
| 60 | + // 初始化分片 |
| 61 | + struct ufile_mutipart_state state; |
| 62 | + error = ufile_multiple_upload_init(&state, bucket_name, key, mime_type); |
| 63 | + if(UFILE_HAS_ERROR(error.code)){ |
| 64 | + ufile_sdk_cleanup(); |
| 65 | + printf("调用 ufile_multiple_upload_init 失败，错误信息为：%d, %s\n", error.code, error.message); |
| 66 | + return 1; |
| 67 | + } |
| 68 | + |
| 69 | + FILE *fp = fopen(file_path, "rb"); |
| 70 | + if (fp == NULL){ |
| 71 | + fprintf(stderr, "打开文件失败, 错误信息为: %s\n", strerror(errno)); |
| 72 | + return 1; |
| 73 | + } |
| 74 | + |
| 75 | + // 上传分片 |
| 76 | + char *buf = malloc(state.part_size); |
| 77 | + for(int i=0; ; i++){ |
| 78 | + size_t nc = fread(buf, 1, state.part_size, fp); |
| 79 | + if(nc == 0){ // 为0即读到文件尾，分片已上传完毕 |
| 80 | + break; |
| 81 | + } |
| 82 | + error = ufile_multiple_upload_part(&state, buf, nc, i); |
| 83 | + if(UFILE_HAS_ERROR(error.code)){ |
| 84 | + printf("调用 ufile_multiple_upload_part 失败，错误信息为：%d, %s\n", error.code, error.message); |
| 85 | + // 分片上传出错，放弃分片 |
| 86 | + ufile_multiple_upload_abort(&state); |
| 87 | + ufile_sdk_cleanup(); |
| 88 | + return 1; |
| 89 | + } |
| 90 | + } |
| 91 | + |
| 92 | + // 完成分片上传 |
| 93 | + printf("调用 ufile_multiple_upload_finish 完成分片上传\n"); |
| 94 | + error = ufile_multiple_upload_finish(&state); |
| 95 | + if(UFILE_HAS_ERROR(error.code)){ |
| 96 | + printf("调用 ufile_multiple_upload_finish 失败，错误信息为：%s\n", error.message); |
| 97 | + } |
| 98 | + // 释放初始化SDK时分配的内存 |
| 99 | + ufile_sdk_cleanup(); |
| 100 | + return 0; |
| 101 | +} |
| 102 | +``` |
| 103 | +</div> |
| 104 | +
|
| 105 | +## 异步并发分片上传 |
| 106 | +
|
| 107 | +注意，当前SDK的异步并发上传功能仅做测试使用，不包含在sdk模块中。线程池模块完整代码请详见[Github](https://github.com/ufilesdk-dev/ufile-csdk/blob/master/lib/thpool.c)。若要使用异步并发分片上传请参照以下示例。如有疑问，可到[Github](https://github.com/ufilesdk-dev/ufile-csdk/issues)上提交issue或[联系我们](https://spt.ucloud.cn/)； |
| 108 | +
|
| 109 | +### 示例 |
| 110 | +
|
| 111 | +> 执行该示例请先配置`UFILE_*`相关环境变量并赋予`bucket_name`、`key`、`mime_type`和`file_path`有效值。 |
| 112 | +
|
| 113 | +<div class="copyable" markdown="1"> |
| 114 | +
|
| 115 | +```c |
| 116 | +#include "../lib/api.h" |
| 117 | +#include <stdio.h> |
| 118 | +#include <stdlib.h> |
| 119 | +#include <errno.h> |
| 120 | +#include <string.h> |
| 121 | +#include "thpool.h" //线程池模块，仅做为测试用，不包含在sdk模块中。 |
| 122 | +
|
| 123 | +const char* bucket_name = "your bucket name"; |
| 124 | +const char* key = "your file key"; |
| 125 | +const char* file_path = "your local file to be uploaded"; |
| 126 | +const char* mime_type = "your file type"; |
| 127 | +const int jobs = 5; |
| 128 | +
|
| 129 | +struct part_data{ |
| 130 | + struct ufile_mutipart_state *state; |
| 131 | + char *buf; |
| 132 | + size_t buf_len; |
| 133 | + int pos; |
| 134 | +}; |
| 135 | +
|
| 136 | +// 线程的分片上传任务，param为分片数据 |
| 137 | +void upload_task(void *param){ |
| 138 | + struct part_data *part = (struct part_data*)param; |
| 139 | + struct ufile_error error; |
| 140 | + error = ufile_multiple_upload_part(part->state, part->buf, part->buf_len, part->pos); |
| 141 | + if(UFILE_HAS_ERROR(error.code)){ |
| 142 | + printf("调用 upload 失败，错误信息为：%s\n", error.message); |
| 143 | + ufile_multiple_upload_abort(part->state); // 某一分片上传失败，则放弃分片上传 |
| 144 | + exit(1); //某一分片上传失败，放弃分片上传后直接退出程序。 |
| 145 | + } |
| 146 | + free(part->buf); |
| 147 | + free(part); |
| 148 | +} |
| 149 | +
|
| 150 | +
|
| 151 | +int main(int argc, char *argv[]){ |
| 152 | + // 读取配置初始化SDK |
| 153 | + struct ufile_config cfg; |
| 154 | + cfg.public_key = getenv("UFILE_PUBLIC_KEY"); |
| 155 | + cfg.private_key = getenv("UFILE_PRIVATE_KEY"); |
| 156 | + cfg.bucket_host = getenv("UFILE_BUCKET_HOST"); |
| 157 | + cfg.file_host = getenv("UFILE_FILE_HOST"); |
| 158 | + struct ufile_error error; |
| 159 | + error = ufile_sdk_initialize(cfg, 0); |
| 160 | + if(UFILE_HAS_ERROR(error.code)){ |
| 161 | + printf("初始化 sdk 失败，错误信息为：%s\n", error.message); |
| 162 | + return 1; |
| 163 | + } |
| 164 | +
|
| 165 | + // 初始化分片 |
| 166 | + struct ufile_mutipart_state state; |
| 167 | + error = ufile_multiple_upload_init(&state, bucket_name, key, file_path); |
| 168 | + if(UFILE_HAS_ERROR(error.code)){ |
| 169 | + ufile_sdk_cleanup(); |
| 170 | + printf("调用 ufile_multiple_upload_init 失败，错误信息为：%d, %s\n", error.code, error.message); |
| 171 | + return 1; |
| 172 | + } |
| 173 | + // 初始化线程池，线程数量为 jobs |
| 174 | + threadpool thpool = thpool_init(jobs); |
| 175 | + |
| 176 | + FILE *fp = fopen(file_path, "rb"); |
| 177 | + int i; |
| 178 | + for(i=0; ; i++){ |
| 179 | + struct part_data *part = malloc(sizeof(struct part_data)); |
| 180 | + part->state = &state; |
| 181 | + part->buf = malloc(state.part_size); |
| 182 | + part->buf_len = fread(part->buf, 1, state.part_size, fp); |
| 183 | + part->pos = i; |
| 184 | + if(part->buf_len == 0){ |
| 185 | + free(part->buf); |
| 186 | + free(part); |
| 187 | + break; |
| 188 | + } |
| 189 | + // 为每个分片添加一个分片任务到线程池的工作队列中 |
| 190 | + thpool_add_work(thpool, &upload_task, part); |
| 191 | + } |
| 192 | + // 等待线程池中的所有分片上传任务完成 |
| 193 | + thpool_wait(thpool); |
| 194 | + // 分片上传任务完成，销毁线程池 |
| 195 | + thpool_destroy(thpool); |
| 196 | + // 完成分片上传 |
| 197 | + error = ufile_multiple_upload_finish(&state); |
| 198 | + if(UFILE_HAS_ERROR(error.code)){ |
| 199 | + printf("调用 ufile_multiple_upload_part 失败，错误信息为：%s\n", error.message); |
| 200 | + } |
| 201 | + // 释放初始化SDK时分配的内存 |
| 202 | + ufile_sdk_cleanup(); |
| 203 | + return 0; |
| 204 | +} |
| 205 | +``` |
| 206 | +</div> |
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