#include <sys/types.h>
#include <unistd.h> 
#include <stdio.h> 
#include <stdlib.h>
#include <assert.h>
#include <errno.h>
#include <sys/time.h>
#include <time.h>
#include <string.h>
#include <curl/curl.h>

#include "tango_cache_transfer.h"
#include "tango_cache_xml.h"
#include "tango_cache_tools.h"

//response body很短或不关心时
size_t curl_response_any_cb(void *ptr, size_t size, size_t count, void *userp)
{
	return size*count;
}

static size_t curl_put_multipart_header_cb(void *ptr, size_t size, size_t count, void *userp)
{
	struct buffer_cache_list *list = (struct buffer_cache_list *)userp;
	size_t totallen = size*count;
	char *start = (char *)ptr, *end = start + totallen;

	if(list->etag == NULL && !strncmp(start, "Etag:", totallen>5?5:totallen))
	{
		start += 5; end -= 1; totallen -= 5;
		while(totallen>0 && (*start==' ')) {start++; totallen--;}
		while(totallen>0 && (*end=='\r'||*end=='\n')) {end--; totallen--;}
		if(totallen > 0)
		{
			totallen = end - start + 1;
			list->etag = (char *)malloc(totallen + 1);
			memcpy(list->etag, start, totallen);
			*(list->etag + totallen) = '\0';
		}
	}
	
	return size*count;
}

static size_t curl_put_once_send_cb(void *ptr, size_t size, size_t count, void *userp)
{
	size_t len;
	struct tango_cache_ctx *ctx = (struct tango_cache_ctx *)userp;

	if(size==0 || count==0 || ctx->response.len>=ctx->response.size)
	{
		return 0; //不一定调用
	}

	len = ctx->response.size - ctx->response.len; //剩余待上传的长度
	if(len > size * count)
	{
		len = size * count;
	}

	memcpy(ptr, ctx->response.buff + ctx->response.len, len);
	ctx->response.len += len;

	if(ctx->response.len >= ctx->response.size)
	{
		ctx->instance->statistic.memory_used -= ctx->response.size; //未使用cache buffer，自己计算内存增减
		if(ctx->way == PUT_ONCE_COPY)
		{
			response_buffer_destroy(&ctx->response);
		}
		else
		{
			ctx->response.buff = NULL;
			ctx->response.len = ctx->response.size = 0;
		}
	}
	return len;
}

static size_t curl_put_multipart_send_cb(void *ptr, size_t size, size_t count, void *userp)
{
	size_t len=0, needlen=size * count, remainlen;
	struct buffer_cache_list *list = (struct buffer_cache_list *)userp;
	struct cache_buffer *next_cache;

	if(size==0 || count==0 || list->cache_cur==NULL)
	{
		return 0;
	}

	while(len<needlen && list->cache_cur!=NULL)
	{
		remainlen = list->cache_cur->len - list->cache_cur->off;
		if(needlen-len >= remainlen)
		{
			memcpy((char*)ptr+len, list->cache_cur->buf+list->cache_cur->off, remainlen);
			len += remainlen;
			
			next_cache = TAILQ_NEXT(list->cache_cur, node);
			TAILQ_REMOVE(&list->cache_list, list->cache_cur, node);
			buffer_cache_destroy(list->cache_cur, list->ctx->instance);
			list->cache_cur = next_cache;
		}
		else
		{
			memcpy((char*)ptr+len, list->cache_cur->buf+list->cache_cur->off, needlen-len);
			list->cache_cur->off += needlen-len;
			len = needlen;
		}
	}
	
	return len;
}

//return value: <0:fail; =0: not exec; >0: OK
int http_put_bodypart_request(struct tango_cache_ctx *ctx, struct buffer_cache_list *list, bool full)
{
	CURLMcode rc;
	char minio_url[256];

	list->cache_cur = TAILQ_FIRST(&list->cache_list);
	if(list->cache_cur == NULL)
	{
		return 0; //已经上传过
	}
	if(NULL == (list->curl=curl_easy_init())) 
	{
		return -1;
	}

	if(full)
	{
		snprintf(minio_url, 256, "http://%s/%s/%s", ctx->instance->minio_hostlist, ctx->instance->bucketname, ctx->file_key);
	}
	else
	{
		snprintf(minio_url, 256, "http://%s/%s/%s?partNumber=%d&uploadId=%s", ctx->instance->minio_hostlist, ctx->instance->bucketname, ctx->file_key, list->part_number, ctx->uploadID);
		curl_easy_setopt(list->curl, CURLOPT_HEADERFUNCTION, curl_put_multipart_header_cb);
		curl_easy_setopt(list->curl, CURLOPT_HEADERDATA, list);
	}
	curl_easy_setopt(list->curl, CURLOPT_URL, minio_url);
	curl_easy_setopt(list->curl, CURLOPT_USERAGENT, "aws-sdk-cpp/1.5.24 Linux/3.10.0-327.el7.x86_64 x86_64 pangu_cache");
	curl_easy_setopt(list->curl, CURLOPT_NOSIGNAL, 1L);
	curl_easy_setopt(list->curl, CURLOPT_WRITEFUNCTION, curl_response_any_cb);
	curl_easy_setopt(list->curl, CURLOPT_WRITEDATA, list);
	curl_easy_setopt(list->curl, CURLOPT_ERRORBUFFER, ctx->error);
	curl_easy_setopt(list->curl, CURLOPT_PRIVATE, ctx);
	curl_easy_setopt(list->curl, CURLOPT_FOLLOWLOCATION, 1L);
	curl_easy_setopt(list->curl, CURLOPT_CONNECTTIMEOUT_MS, 500L); 
	curl_easy_setopt(list->curl, CURLOPT_HTTPHEADER, ctx->headers_puts);
	curl_easy_setopt(list->curl, CURLOPT_LOW_SPEED_TIME, 2L);
	curl_easy_setopt(list->curl, CURLOPT_LOW_SPEED_LIMIT, 1024L);

	curl_easy_setopt(list->curl, CURLOPT_UPLOAD, 1L);
	curl_easy_setopt(list->curl, CURLOPT_INFILESIZE, list->length);
	curl_easy_setopt(list->curl, CURLOPT_READFUNCTION, curl_put_multipart_send_cb);
	curl_easy_setopt(list->curl, CURLOPT_READDATA, list);

	rc = curl_multi_add_handle(ctx->instance->multi_hd, list->curl);
	assert(rc==CURLM_OK);
	return 1;
}

static size_t curl_write_uploadID_cb(void *ptr, size_t size, size_t count, void *userp)
{
	struct tango_cache_ctx *ctx = (struct tango_cache_ctx *)userp;
	struct easy_string *estr = &ctx->response;
	CURLcode code;

	if(ctx->fail_state)
	{
	   return size*count;
	}

	if(ctx->res_code == 0)
	{
		code = curl_easy_getinfo(ctx->curl, CURLINFO_RESPONSE_CODE, &ctx->res_code);
		if(code != CURLE_OK || ctx->res_code!=200L)
		{
			ctx->fail_state = true;
			ctx->error_code = CACHE_CACHE_MISS;
			if(code != CURLE_OK) MESA_HANDLE_RUNTIME_LOGV2(ctx->instance->runtime_log, RLOG_LV_DEBUG, "%s", ctx->error);
			return size*count;
		}
	}
	
	if(estr->size-estr->len < size*count+1)
	{
		estr->size += size*count*2+1;
		estr->buff = (char*)realloc(estr->buff,estr->size);
	}
	
	memcpy(estr->buff+estr->len,ptr,size*count);
	estr->len+=size*count;
	estr->buff[estr->len]='\0';
	return size*count;
}

int curl_get_minio_uploadID(struct tango_cache_ctx *ctx)
{
	CURLMcode rc;
	char minio_url[256];
	
	if(NULL == (ctx->curl=curl_easy_init())) 
	{
		free(ctx);
		return -1;
	}
	
	snprintf(minio_url, 256, "http://%s/%s/%s?uploads", ctx->instance->minio_hostlist, ctx->instance->bucketname, ctx->file_key);
	curl_easy_setopt(ctx->curl, CURLOPT_POST, 1L);
	curl_easy_setopt(ctx->curl, CURLOPT_URL, minio_url);
	curl_easy_setopt(ctx->curl, CURLOPT_USERAGENT, "aws-sdk-cpp/1.5.24 Linux/3.10.0-327.el7.x86_64 x86_64 pangu_cache");
	curl_easy_setopt(ctx->curl, CURLOPT_NOSIGNAL,1L);
	curl_easy_setopt(ctx->curl, CURLOPT_WRITEFUNCTION, curl_write_uploadID_cb);
	curl_easy_setopt(ctx->curl, CURLOPT_WRITEDATA, ctx);
	curl_easy_setopt(ctx->curl, CURLOPT_ERRORBUFFER, ctx->error);
	curl_easy_setopt(ctx->curl, CURLOPT_PRIVATE, ctx);
	curl_easy_setopt(ctx->curl, CURLOPT_FOLLOWLOCATION, 1L);
	curl_easy_setopt(ctx->curl, CURLOPT_CONNECTTIMEOUT_MS, 500L); 
	curl_easy_setopt(ctx->curl, CURLOPT_HTTPHEADER, ctx->headers_puts);
	curl_easy_setopt(ctx->curl, CURLOPT_LOW_SPEED_TIME, 2L);
	curl_easy_setopt(ctx->curl, CURLOPT_LOW_SPEED_LIMIT, 1024L);

	rc = curl_multi_add_handle(ctx->instance->multi_hd, ctx->curl);
	assert(rc==CURLM_OK);
	return 1;
}

bool cache_delete_minio_object(struct tango_cache_ctx *ctx)
{
	CURLMcode rc;
	char minio_url[256];

	if(NULL == (ctx->curl=curl_easy_init())) 
	{
		return false;
	}

	snprintf(minio_url, 256, "http://%s/%s/%s", ctx->instance->minio_hostlist, ctx->instance->bucketname, ctx->file_key);
	curl_easy_setopt(ctx->curl, CURLOPT_CUSTOMREQUEST, "DELETE");
	curl_easy_setopt(ctx->curl, CURLOPT_URL, minio_url);
	curl_easy_setopt(ctx->curl, CURLOPT_USERAGENT, "aws-sdk-cpp/1.5.24 Linux/3.10.0-327.el7.x86_64 x86_64 pangu_cache");
	curl_easy_setopt(ctx->curl, CURLOPT_NOSIGNAL, 1L);
	curl_easy_setopt(ctx->curl, CURLOPT_WRITEFUNCTION, curl_response_any_cb);
	curl_easy_setopt(ctx->curl, CURLOPT_WRITEDATA, ctx);
	curl_easy_setopt(ctx->curl, CURLOPT_ERRORBUFFER, ctx->error);
	curl_easy_setopt(ctx->curl, CURLOPT_PRIVATE, ctx);
	curl_easy_setopt(ctx->curl, CURLOPT_FOLLOWLOCATION, 1L);
	curl_easy_setopt(ctx->curl, CURLOPT_CONNECTTIMEOUT_MS, 500L); 

	rc = curl_multi_add_handle(ctx->instance->multi_hd, ctx->curl);
	assert(rc==CURLM_OK);
	return true;
}

//return value: true-成功添加事件；false-未添加事件
bool cache_cancel_upload_minio(struct tango_cache_ctx *ctx)
{
	CURLMcode rc;
	char minio_url[256];

	if(NULL == (ctx->curl=curl_easy_init())) 
	{
		return false;
	}

	snprintf(minio_url, 256, "http://%s/%s/%s?uploadId=%s", ctx->instance->minio_hostlist, ctx->instance->bucketname, ctx->file_key, ctx->uploadID);
	curl_easy_setopt(ctx->curl, CURLOPT_CUSTOMREQUEST, "DELETE");
	curl_easy_setopt(ctx->curl, CURLOPT_URL, minio_url);
	curl_easy_setopt(ctx->curl, CURLOPT_USERAGENT, "aws-sdk-cpp/1.5.24 Linux/3.10.0-327.el7.x86_64 x86_64 pangu_cache");
	curl_easy_setopt(ctx->curl, CURLOPT_NOSIGNAL, 1L);
	curl_easy_setopt(ctx->curl, CURLOPT_WRITEFUNCTION, curl_response_any_cb);
	curl_easy_setopt(ctx->curl, CURLOPT_WRITEDATA, ctx);
	curl_easy_setopt(ctx->curl, CURLOPT_ERRORBUFFER, ctx->error);
	curl_easy_setopt(ctx->curl, CURLOPT_PRIVATE, ctx);
	curl_easy_setopt(ctx->curl, CURLOPT_FOLLOWLOCATION, 1L);
	curl_easy_setopt(ctx->curl, CURLOPT_CONNECTTIMEOUT_MS, 500L); 

	rc = curl_multi_add_handle(ctx->instance->multi_hd, ctx->curl);
	assert(rc==CURLM_OK);
	return true;
}

//return value: true-成功添加事件；false-未添加事件
bool cache_kick_combine_minio(struct tango_cache_ctx *ctx)
{
	int len=0;
	CURLMcode rc;
	char minio_url[256];
	
	if(NULL == (ctx->curl=curl_easy_init())) 
	{
		return false;
	}
	construct_complete_xml(ctx, &ctx->combine_xml, &len);
	
	snprintf(minio_url, 256, "http://%s/%s/%s?uploadId=%s", ctx->instance->minio_hostlist, ctx->instance->bucketname, ctx->file_key, ctx->uploadID);
	curl_easy_setopt(ctx->curl, CURLOPT_POST, 1L);
	curl_easy_setopt(ctx->curl, CURLOPT_URL, minio_url);
	curl_easy_setopt(ctx->curl, CURLOPT_USERAGENT, "aws-sdk-cpp/1.5.24 Linux/3.10.0-327.el7.x86_64 x86_64 pangu_cache");
	curl_easy_setopt(ctx->curl, CURLOPT_NOSIGNAL,1L);
	curl_easy_setopt(ctx->curl, CURLOPT_WRITEFUNCTION, curl_response_any_cb);
	curl_easy_setopt(ctx->curl, CURLOPT_WRITEDATA, ctx);
	curl_easy_setopt(ctx->curl, CURLOPT_ERRORBUFFER, ctx->error);
	curl_easy_setopt(ctx->curl, CURLOPT_PRIVATE, ctx);
	curl_easy_setopt(ctx->curl, CURLOPT_FOLLOWLOCATION, 1L);
	curl_easy_setopt(ctx->curl, CURLOPT_CONNECTTIMEOUT_MS, 500L);
	
	curl_easy_setopt(ctx->curl, CURLOPT_POSTFIELDS, ctx->combine_xml);
	curl_easy_setopt(ctx->curl, CURLOPT_POSTFIELDSIZE, len); //填充Content-Length

	ctx->headers = curl_slist_append(ctx->headers, "Content-Type: application/xml");
	curl_easy_setopt(ctx->curl, CURLOPT_HTTPHEADER, ctx->headers);

	rc = curl_multi_add_handle(ctx->instance->multi_hd, ctx->curl);
	assert(rc==CURLM_OK);
	return true;
}

//return value: true-成功添加事件；false-未添加事件
bool cache_kick_upload_minio_multipart(struct tango_cache_ctx *ctx, struct buffer_cache_list *list)
{
	int ret = 1;

	if(ctx->fail_state)
	{
		return false;
	}

	switch(ctx->put_state)
	{
		case PUT_STATE_START:
			ctx->put_state = PUT_STATE_WAIT_START;
			ret = curl_get_minio_uploadID(ctx);
			break;

		case PUT_STATE_START_DONE:
		case PUT_STATE_PART:
			ret = http_put_bodypart_request(ctx, list, false);
			if(ret > 0)
			{
				ctx->part_runing_num++;
			}
			break;
			
		default: break;//nothing to do
	}
	
	if(ret <= 0)
	{
		ctx->fail_state = true;
		ctx->error_code = CACHE_ERR_CURL;
		return false;
	}
	return true;
}

int cache_kick_upload_minio_end(struct tango_cache_ctx *ctx)
{
	int ret = 0;

	ctx->close_state = true;//仅设置状态，并非真正关闭；内部状态机轮转结束后再关闭
	if(ctx->fail_state)
	{
		tango_cache_ctx_destroy(ctx);
		return 0;
	}
	
	switch(ctx->put_state)
	{
		case PUT_STATE_START:
			ctx->put_state = PUT_STATE_END;
			if(ctx->list_cur->cache_cur->len > 0)
			{
				TAILQ_INSERT_TAIL(&ctx->list_cur->cache_list, ctx->list_cur->cache_cur, node);
				ctx->list_cur->length += ctx->list_cur->cache_cur->len;
				ret = http_put_bodypart_request(ctx, ctx->list_cur, true);
				if(ret <= 0)
				{
					tango_cache_ctx_destroy(ctx);
				}
			}
			else
			{
				tango_cache_ctx_destroy(ctx);
			}
			break;
			
		case PUT_STATE_PART:
			if(ctx->list_cur->length + ctx->list_cur->cache_cur->len > 0)
			{
				TAILQ_INSERT_TAIL(&ctx->list_cur->cache_list, ctx->list_cur->cache_cur, node);
				ctx->list_cur->length += ctx->list_cur->cache_cur->len;
				ctx->list_cur->cache_cur = NULL;
				TAILQ_INSERT_TAIL(&ctx->cache_head, ctx->list_cur, node);
				cache_kick_upload_minio_multipart(ctx, ctx->list_cur);
				ctx->list_cur = NULL;
			}
			else 
			{
				buffer_cache_list_destroy(ctx->list_cur, ctx);
				ctx->list_cur = NULL;
				if(ctx->part_runing_num==0) //已全部上传完成，而且END时无数据块了
				{
					if(cache_kick_combine_minio(ctx))
					{
						ctx->put_state = PUT_STATE_END;
					}
					else
					{
						tango_cache_ctx_destroy(ctx);
					}
				}	
			}
			break;
			
		case PUT_STATE_END: assert(0); //用户主动调用end时不可能处于此状态
		case PUT_STATE_WAIT_START: //此时未获取到uploadId，所以无法触发上传
		default: break;
	}

	return ret;
}

void tango_cache_curl_put_done(CURL *easy, struct tango_cache_ctx *ctx, CURLcode res, long res_code)
{
	struct buffer_cache_list *list;

	switch(ctx->put_state)
	{
		case PUT_STATE_WAIT_START:
			ctx->curl = NULL;
			ctx->res_code = 0;
			curl_multi_remove_handle(ctx->instance->multi_hd, easy);
			curl_easy_cleanup(easy);
			if(res!=CURLE_OK||res_code!=200L|| ctx->fail_state || !parse_uploadID_xml(ctx->response.buff, ctx->response.len, &ctx->uploadID))
			{
				response_buffer_destroy(&ctx->response);
				ctx->error_code = CACHE_ERR_CURL;
				ctx->fail_state = true;
				if(res != CURLE_OK) MESA_HANDLE_RUNTIME_LOGV2(ctx->instance->runtime_log, RLOG_LV_DEBUG, "%s", ctx->error);
			}
			else
			{
				free(ctx->response.buff);
				ctx->response.buff = NULL;
				ctx->put_state = PUT_STATE_START_DONE;
				TAILQ_FOREACH(list, &ctx->cache_head, node)
				{
					if(!cache_kick_upload_minio_multipart(ctx, list))
					{
						ctx->fail_state = true;
						break;
					}
					else
					{
						ctx->put_state = PUT_STATE_PART;
					}
				}
			}
			if(ctx->close_state)
			{
				if(!ctx->fail_state)
				{
					cache_kick_upload_minio_end(ctx);
				}
				else if(ctx->put_state!=PUT_STATE_PART)
				{
					tango_cache_ctx_destroy(ctx);
				}
			}
			break;

		case PUT_STATE_PART:
			curl_multi_remove_handle(ctx->instance->multi_hd, easy);
			curl_easy_cleanup(easy);
			ctx->part_runing_num--;
			TAILQ_FOREACH(list, &ctx->cache_head, node)
			{
				if(list->curl == easy)
				{
					list->curl = NULL;
					break;
				}
			}
			assert(list != NULL); //PART状态不被打断
			if(res != CURLE_OK ||res_code!=200L )
			{
				ctx->fail_state = true;
				if(res != CURLE_OK) MESA_HANDLE_RUNTIME_LOGV2(ctx->instance->runtime_log, RLOG_LV_DEBUG, "%s", ctx->error);
			}
			if(ctx->part_runing_num==0 && ctx->list_cur==NULL)
			{
				if(ctx->fail_state && cache_cancel_upload_minio(ctx))
				{
					ctx->put_state = PUT_STATE_CANCEL;
				}
				else if(!ctx->fail_state && ctx->close_state && cache_kick_combine_minio(ctx))
				{
					ctx->put_state = PUT_STATE_END;
				}
				else if(ctx->close_state)
				{
					tango_cache_ctx_destroy(ctx);
				}
			}
			break;
			
		case PUT_STATE_CANCEL: //等待关闭
			ctx->curl = NULL;
			ctx->res_code = 0;
			curl_multi_remove_handle(ctx->instance->multi_hd, easy);
			curl_easy_cleanup(easy);
			if(ctx->close_state)
			{
				tango_cache_ctx_destroy(ctx);
			}
			break;
			
		case PUT_STATE_END:
			if(res != CURLE_OK || res_code!=200L)
			{
				ctx->fail_state = true;
				if(res != CURLE_OK) MESA_HANDLE_RUNTIME_LOGV2(ctx->instance->runtime_log, RLOG_LV_DEBUG, "%s", ctx->error);
			}
			tango_cache_ctx_destroy(ctx);
			break;
		default: break;
	}
}

int tango_cache_upload_once_start(struct tango_cache_ctx *ctx, const char *data, size_t size)
{
	CURLMcode rc;
	char minio_url[256];

	if(NULL == (ctx->curl=curl_easy_init())) 
	{
		tango_cache_ctx_destroy(ctx);
		if(ctx->way == PUT_ONCE_FREE)
		{
			free((void *)data);
		}
		return -1;
	}
	ctx->put_state = PUT_STATE_END;

	snprintf(minio_url, 256, "http://%s/%s/%s", ctx->instance->minio_hostlist, ctx->instance->bucketname, ctx->file_key);
	curl_easy_setopt(ctx->curl, CURLOPT_URL, minio_url);
	curl_easy_setopt(ctx->curl, CURLOPT_USERAGENT, "aws-sdk-cpp/1.5.24 Linux/3.10.0-327.el7.x86_64 x86_64 pangu_cache");
	curl_easy_setopt(ctx->curl, CURLOPT_NOSIGNAL, 1L);
	curl_easy_setopt(ctx->curl, CURLOPT_WRITEFUNCTION, curl_response_any_cb);
	curl_easy_setopt(ctx->curl, CURLOPT_WRITEDATA, ctx);
	curl_easy_setopt(ctx->curl, CURLOPT_ERRORBUFFER, ctx->error);
	curl_easy_setopt(ctx->curl, CURLOPT_PRIVATE, ctx);
	curl_easy_setopt(ctx->curl, CURLOPT_FOLLOWLOCATION, 1L);
	curl_easy_setopt(ctx->curl, CURLOPT_CONNECTTIMEOUT_MS, 500L); 
	curl_easy_setopt(ctx->curl, CURLOPT_HTTPHEADER, ctx->headers_puts);
	curl_easy_setopt(ctx->curl, CURLOPT_LOW_SPEED_TIME, 2L);
	curl_easy_setopt(ctx->curl, CURLOPT_LOW_SPEED_LIMIT, 1024L);

	if(ctx->way == PUT_ONCE_COPY)
	{
		ctx->response.buff = (char *)malloc(size);
		memcpy(ctx->response.buff, data, size);
	}
	else
	{
		ctx->response.buff = (char *)data;
	}
	ctx->response.size = size;
	ctx->response.len = 0;
	ctx->instance->statistic.memory_used += size;
	curl_easy_setopt(ctx->curl, CURLOPT_UPLOAD, 1L);
	curl_easy_setopt(ctx->curl, CURLOPT_INFILESIZE, ctx->response.size);
	curl_easy_setopt(ctx->curl, CURLOPT_READFUNCTION, curl_put_once_send_cb);
	curl_easy_setopt(ctx->curl, CURLOPT_READDATA, ctx);

	rc = curl_multi_add_handle(ctx->instance->multi_hd, ctx->curl);
	assert(rc==CURLM_OK);
	return 0;
}

void tango_cache_curl_get_done(CURL *easy, struct tango_cache_ctx *ctx, CURLcode res, long res_code)
{
	curl_multi_remove_handle(ctx->instance->multi_hd, easy);
	curl_easy_cleanup(easy);
	ctx->curl = NULL;

	switch(ctx->get_state)
	{
		case GET_STATE_START:
			if(!ctx->fail_state)
			{
				if(res!=CURLE_OK || res_code!=200L)
				{
					ctx->error_code = CACHE_ERR_CURL;
					promise_failed(future_to_promise(ctx->future), FUTURE_ERROR_CANCEL, ctx->error);
				}
				else
				{
					promise_success(future_to_promise(ctx->future), NULL);
				}
			}
			tango_cache_ctx_destroy(ctx);
			break;
			
		case GET_STATE_DELETE:
			if(cache_delete_minio_object(ctx))
			{
				ctx->get_state = GET_STATE_END;
			}
			else
			{
				tango_cache_ctx_destroy(ctx);
			}
			break;
			
		case GET_STATE_END:
			tango_cache_ctx_destroy(ctx);
			break;
		default: assert(0);break;
	}
}

static size_t curl_get_response_body_cb(void *ptr, size_t size, size_t count, void *userp)
{
	struct tango_cache_ctx *ctx = (struct tango_cache_ctx *)userp;
	struct tango_cache_result result;

	if(ctx->fail_state || ctx->get_state==GET_STATE_DELETE)
	{
		return size*count;
	}
	
	if(!ctx->expire_comes) //无Expires时
	{
		ctx->fail_state = true;
		ctx->error_code = CACHE_CACHE_MISS;
		ctx->get_state	= GET_STATE_DELETE;
		promise_failed(future_to_promise(ctx->future), FUTURE_ERROR_CANCEL, "cache Expires not found");
	}
	else
	{
		result.data_frag = ptr;
		result.size = size * count;
		result.type = RESULT_TYPE_BODY;
		promise_success(future_to_promise(ctx->future), &result);
	}
	return size*count;
}

static size_t curl_get_response_header_cb(void *ptr, size_t size, size_t count, void *userp)
{
	struct tango_cache_ctx *ctx = (struct tango_cache_ctx *)userp;
	CURLcode code;
	struct tango_cache_result result;
	char *start=(char *)ptr, *pos_colon, *hdrdata=(char*)ptr;
	bool ptr_valid=false;
	size_t raw_len = size*count, hdrlen=size*count;

	if(ctx->fail_state || ctx->get_state==GET_STATE_DELETE)
	{
		return raw_len;
	}

	if(ctx->res_code==0) //首次应答时先看应答码是否是200
	{
		code = curl_easy_getinfo(ctx->curl, CURLINFO_RESPONSE_CODE, &ctx->res_code);
		if(code != CURLE_OK || ctx->res_code!=200L)
		{
			ctx->fail_state = true;
			ctx->error_code = CACHE_CACHE_MISS;
			promise_failed(future_to_promise(ctx->future), FUTURE_ERROR_CANCEL, "cache not hit");
			if(code != CURLE_OK) MESA_HANDLE_RUNTIME_LOGV2(ctx->instance->runtime_log, RLOG_LV_DEBUG, "%s", ctx->error);
			return raw_len;
		}
	}

	if((pos_colon=(char*)memchr(start, ':', raw_len))!=NULL)
	{
		size_t datalen = pos_colon - start;
		switch(datalen)
		{
			case 7:
				if(strcmp_one_word_mesa_equal_len("expires", "EXPIRES", start, 7))
				{
					time_t expire = expires_hdr2timestamp(pos_colon + 1, raw_len - datalen - 1);
					time_t time_gmt = get_gmtime_timestamp(time(NULL));
					if(time_gmt + ctx->relative_age > expire) //缓存失效；TODO relative_age的含义是啥
					{
						ctx->fail_state = true;
						ctx->error_code = CACHE_TIMEOUT;
						if(time_gmt>=expire) ctx->get_state  = GET_STATE_DELETE; //缓存失效时在下载完毕时触发删除动作
						response_buffer_destroy(&ctx->response);
						promise_failed(future_to_promise(ctx->future), FUTURE_ERROR_CANCEL, "cache not fresh");
						return raw_len;
					}
					else if(ctx->response.buff != NULL)
					{
						result.data_frag = ctx->response.buff;
						result.size = ctx->response.len;
						result.type = RESULT_TYPE_HEADER;
						promise_success(future_to_promise(ctx->future), &result);
						response_buffer_destroy(&ctx->response);
					}
					ctx->expire_comes = true;
				}
				break;
			case 15:
				if(strcmp_one_word_mesa_equal_len("x-amz-meta-user", "X-AMZ-META-USER", start, 15))
				{
					if(ctx->response.size-ctx->response.len < raw_len+1)
					{
						ctx->response.size += raw_len*8 + 1;
						ctx->response.buff = (char*)realloc(ctx->response.buff, ctx->response.size);
					}
					if((hdrlen = Base64_DecodeBlock((unsigned char*)pos_colon+1, raw_len-datalen-1, (unsigned char*)ctx->response.buff+ctx->response.len, ctx->response.size-ctx->response.len))>0)
					{
						hdrdata = ctx->response.buff+ctx->response.len;
						ptr_valid = true;
					}
				}
				break;
			case 11: if(strcmp_one_word_mesa_equal_len("content-md5", "CONTENT-MD5", start, 11)) ptr_valid = true; break;
			case 12: if(strcmp_one_word_mesa_equal_len("content-type", "CONTENT-TYPE", start, 12)) ptr_valid = true; break;
			case 14: if(strcmp_one_word_mesa_equal_len("content-length", "CONTENT-LENGTH", start, 14)) ptr_valid = true; break;
			case 16: if(strcmp_one_word_mesa_equal_len("content-encoding", "CONTENT-ENCODING", start, 16)) ptr_valid = true; break;
			case 19: if(strcmp_one_word_mesa_equal_len("content-disposition", "CONTENT-DISPOSITION", start, 19)) ptr_valid = true; break;
			default: break;
		}
	}

	if(ptr_valid)
	{
		if(ctx->expire_comes)
		{
			result.data_frag = hdrdata;
			result.size = hdrlen;
			result.type = RESULT_TYPE_HEADER;
			promise_success(future_to_promise(ctx->future), &result);
		}
		else
		{
			if(ctx->response.size-ctx->response.len < hdrlen+1)
			{
				ctx->response.size += hdrlen*8 + 1;
				ctx->response.buff = (char*)realloc(ctx->response.buff, ctx->response.size);
			}
			memcpy(ctx->response.buff+ctx->response.len, hdrdata, hdrlen);
			ctx->response.len += hdrlen;
			ctx->response.buff[ctx->response.len] = '\0';
		}
	}
	return raw_len;
}

int tango_cache_fetch_start(struct tango_cache_ctx *ctx)
{	
	CURLMcode rc;
	char minio_url[256];

	if(NULL == (ctx->curl=curl_easy_init())) 
	{
		tango_cache_ctx_destroy(ctx);
		return -1;
	}

	snprintf(minio_url, 256, "http://%s/%s/%s", ctx->instance->minio_hostlist, ctx->instance->bucketname, ctx->file_key);
	curl_easy_setopt(ctx->curl, CURLOPT_URL, minio_url);
	curl_easy_setopt(ctx->curl, CURLOPT_USERAGENT, "aws-sdk-cpp/1.5.24 Linux/3.10.0-327.el7.x86_64 x86_64 pangu_cache");
	curl_easy_setopt(ctx->curl, CURLOPT_NOSIGNAL,1L);
	curl_easy_setopt(ctx->curl, CURLOPT_WRITEFUNCTION, curl_get_response_body_cb);
	curl_easy_setopt(ctx->curl, CURLOPT_WRITEDATA, ctx);
	curl_easy_setopt(ctx->curl, CURLOPT_ERRORBUFFER, ctx->error);
	curl_easy_setopt(ctx->curl, CURLOPT_PRIVATE, ctx);
	curl_easy_setopt(ctx->curl, CURLOPT_FOLLOWLOCATION, 1L);
	curl_easy_setopt(ctx->curl, CURLOPT_CONNECTTIMEOUT_MS, 500L); 	
	curl_easy_setopt(ctx->curl, CURLOPT_HEADERFUNCTION, curl_get_response_header_cb);
	curl_easy_setopt(ctx->curl, CURLOPT_HEADERDATA, ctx);
	//ctx->error="Operation too slow. Less than 1024 bytes/sec transferred the last 3 seconds"
	curl_easy_setopt(ctx->curl, CURLOPT_LOW_SPEED_TIME, 2L);
	curl_easy_setopt(ctx->curl, CURLOPT_LOW_SPEED_LIMIT, 1024L);

	rc = curl_multi_add_handle(ctx->instance->multi_hd, ctx->curl);
	assert(rc==CURLM_OK);
	return 0;
}