Golang util.NewBuffer函数代码示例

// 发表评论。入topics_reply库，更新topics和topics_ex库
// objname 注册的评论对象名
func PostComment(objid, objtype, uid int, content string, objname string) error {
	comment := model.NewComment()
	comment.Objid = objid
	comment.Objtype = objtype
	comment.Uid = uid
	comment.Content = content

	// TODO:评论楼层怎么处理，避免冲突？最后的楼层信息保存在内存中？

	// 暂时只是从数据库中取出最后的评论楼层
	stringBuilder := util.NewBuffer()
	stringBuilder.Append("objid=").AppendInt(objid).Append(" AND objtype=").AppendInt(objtype)
	tmpCmt, err := model.NewComment().Where(stringBuilder.String()).Order("ctime DESC").Find()
	if err != nil {
		logger.Errorln("post comment service error:", err)
		return err
	} else {
		comment.Floor = tmpCmt.Floor + 1
	}
	// 入评论库
	cid, err := comment.Insert()
	if err != nil {
		logger.Errorln("post comment service error:", err)
		return err
	}
	// 回调，不关心处理结果（有些对象可能不需要回调）
	if commenter, ok := commenters[objname]; ok {
		logger.Debugf("评论[objid:%d] [objtype:%d] [uid:%d] 成功，通知被评论者更新", objid, objtype, uid)
		go commenter.UpdateComment(cid, objid, uid, time.Now().Format("2006-01-02 15:04:05"))
	}

	return nil
}

// 更新该帖子的回复信息
// cid：评论id；objid：被评论对象id；uid：评论者；cmttime：评论时间
func (self TopicComment) UpdateComment(cid, objid, uid int, cmttime string) {
	tid := strconv.Itoa(objid)
	// 更新最后回复信息
	stringBuilder := util.NewBuffer().Append("lastreplyuid=").AppendInt(uid).Append(",lastreplytime=").Append(cmttime)
	err := model.NewTopic().Set(stringBuilder.String()).Where("tid=" + tid).Update()
	if err != nil {
		logger.Errorln("更新帖子最后回复人信息失败：", err)
	}
	// 更新回复数（TODO：暂时每次都更新表）
	IncrTopicReply(tid, uid)
}

// 发表评论（或回复）。
// objid 注册的评论对象
// uid 评论人
func PostComment(uid, objid int, form url.Values) (*model.Comment, error) {
	comment := model.NewComment()
	comment.Objid = objid
	objtype := util.MustInt(form.Get("objtype"))
	comment.Objtype = objtype
	comment.Uid = uid
	comment.Content = form.Get("content")

	// TODO:评论楼层怎么处理，避免冲突？最后的楼层信息保存在内存中？

	// 暂时只是从数据库中取出最后的评论楼层
	stringBuilder := util.NewBuffer()
	stringBuilder.Append("objid=").AppendInt(objid).Append(" AND objtype=").AppendInt(objtype)
	tmpCmt, err := model.NewComment().Where(stringBuilder.String()).Order("ctime DESC").Find()
	if err != nil {
		logger.Errorln("post comment service error:", err)
		return nil, err
	} else {
		comment.Floor = tmpCmt.Floor + 1
	}
	// 入评论库
	cid, err := comment.Insert()
	if err != nil {
		logger.Errorln("post comment service error:", err)
		return nil, err
	}
	comment.Cid = cid
	comment.Ctime = util.TimeNow()
	decodeCmtContent(comment)

	// 回调，不关心处理结果（有些对象可能不需要回调）
	if commenter, ok := commenters[objtype]; ok {
		logger.Debugf("评论[objid:%d] [objtype:%d] [uid:%d] 成功，通知被评论者更新", objid, objtype, uid)
		go commenter.UpdateComment(cid, objid, uid, time.Now().Format("2006-01-02 15:04:05"))
	}

	// 发评论，活跃度+5
	go IncUserWeight("uid="+strconv.Itoa(uid), 5)

	// 给被评论对象所有者发系统消息
	ext := map[string]interface{}{
		"objid":   objid,
		"objtype": objtype,
		"cid":     cid,
		"uid":     uid,
	}
	go SendSystemMsgTo(0, objtype, ext)

	// @某人 发系统消息
	go SendSysMsgAtUids(form.Get("uid"), ext)
	go SendSysMsgAtUsernames(form.Get("usernames"), ext)

	return comment, nil
}

// 构造update语句中的set部分子句
func GenSetClause(form url.Values, fields []string) string {
	stringBuilder := util.NewBuffer()
	for _, field := range fields {
		if form.Get(field) != "" {
			stringBuilder.Append(",").Append(field).Append("=").Append(form.Get(field))
		}
	}
	if stringBuilder.Len() > 0 {
		return stringBuilder.String()[1:]
	}
	return ""
}

// 查询条件处理（TODO:暂时没有处理between和in）
func (this *Dao) Where(condition string) {
	this.whereVal = make([]interface{}, 0)
	stringBuilder := util.NewBuffer()
	conditions := SplitIn(condition, []string{" and ", " AND ", " or ", " OR "}...)
	for _, condition := range conditions {
		condition = strings.TrimSpace(condition)
		parts := SplitIn(condition, "=", "<", ">")
		if len(parts) >= 3 {
			// 处理不等于
			if strings.HasSuffix(parts[0], "!") {
				stringBuilder.Append("`" + strings.Trim(parts[0], "` !") + "` !")
			} else {
				stringBuilder.Append("`" + strings.Trim(parts[0], "` ") + "`")
			}
			stringBuilder.Append(strings.TrimSpace(parts[1]))
			if len(parts) > 3 {
				// 判断是不是 ">="或"<="
				if strings.ContainsAny(parts[2], "= & < & >") {
					stringBuilder.Append(strings.TrimSpace(parts[2]))
				}
				start := len(parts[0]) + len(parts[1]) + 1
				this.whereVal = append(this.whereVal, strings.TrimSpace(condition[start:]))
			} else {
				this.whereVal = append(this.whereVal, strings.TrimSpace(parts[2]))
			}
			stringBuilder.Append("?")
		} else {
			tmp := strings.ToUpper(parts[0])
			if tmp == "OR" || tmp == "AND" {
				stringBuilder.Append(" ").Append(tmp).Append(" ")
			} else {
				// 处理"in"语句（TODO:用正则处理？）
				if strings.ContainsAny(strings.ToLower(parts[0]), "in & ( & )") {
					ins := Split(parts[0], "(", ")")
					if len(ins) == 3 {
						inVals := strings.Split(ins[1], ",")
						for _, inVal := range inVals {
							this.whereVal = append(this.whereVal, inVal)
						}
						// in中有多少个值
						inLen := len(inVals)
						qms := strings.Repeat("?,", inLen)
						field := ins[0][:len(ins[0])-3]
						stringBuilder.Append("`" + strings.Trim(field, "` ") + "` in").Append("(").Append(qms[:len(qms)-1]).Append(")")
					}
				} else {
					stringBuilder.Append("`" + strings.Trim(parts[0], "` ") + "`")
				}
			}
		}
	}
	this.where = stringBuilder.String()
}

//bug: next page is always same for popular/last/ective and /list/brief
// 构造分页html
// curPage 当前页码；total总记录数; PAGE_NUM 每页显示多少条
func GetPageHtml(curPage, total, PAGE_NUM int) string {
	// 总页数
	pageCount := total / PAGE_NUM
	if total%PAGE_NUM != 0 {
		pageCount++
	}
	if pageCount < 2 {
		return ""
	}
	// 显示5页，然后显示...，接着显示最后两页
	stringBuilder := util.NewBuffer()
	stringBuilder.Append(`<li class="prev previous_page">`)
	// 当前是第一页
	if curPage != 1 {
		stringBuilder.Append(`<a href="/topics?p=` + strconv.Itoa(curPage-1) + `">← 上一页</a>`)
	}
	stringBuilder.Append(`</li>`)
	before := 5
	showPages := 8
	for i := 0; i < pageCount; i++ {
		logger.Traceln(i, pageCount)
		if i >= showPages {
			break
		}
		if curPage == i+1 {
			stringBuilder.Append(`<li class="active"><a href="/topics?p=`).AppendInt(i + 1).Append(`">`).AppendInt(i + 1).Append("</a></li>")
			continue
		}
		// 分界点
		if curPage >= before {
			if curPage >= 7 {
				before = 2
			} else {
				before = curPage + 2
			}
			showPages += 2
		}
		if i == before {
			stringBuilder.Append(`<li class="disabled"><a href="#"><span class="gap">…</span></a></li>`)
			continue
		}
		stringBuilder.Append(`<li><a href="/topics?p=`).AppendInt(i + 1).Append(`">`).AppendInt(i + 1).Append("</a></li>")
	}
	stringBuilder.Append(`<li class="next next_page ">`)
	// 最后一页
	if curPage < pageCount {
		stringBuilder.Append(`<a href="/topics?p=` + strconv.Itoa(curPage+1) + `">下一页 →</a>`)
	}
	stringBuilder.Append(`</li>`)
	return stringBuilder.String()
}

func (this *SolrClient) Post() error {
	stringBuilder := util.NewBuffer().Append("{")

	needComma := false
	for _, addCommand := range this.addCommands {
		commandJson, err := json.Marshal(addCommand)
		if err != nil {
			continue
		}

		if stringBuilder.Len() == 1 {
			needComma = false
		} else {
			needComma = true
		}

		if needComma {
			stringBuilder.Append(",")
		}

		stringBuilder.Append(`"add":`).AppendBytes(commandJson)
	}

	if stringBuilder.Len() == 1 {
		logger.Errorln("post docs:no right addcommand")
		return errors.New("no right addcommand")
	}

	stringBuilder.Append("}")

	resp, err := http.Post(config.Config["engine_url"]+"/update?wt=json&commit=true", "application/json", stringBuilder)
	if err != nil {
		logger.Errorln("post error:", err)
		return err
	}

	defer resp.Body.Close()

	var result map[string]interface{}
	err = json.NewDecoder(resp.Body).Decode(&result)
	if err != nil {
		logger.Errorln("parse response error:", err)
		return err
	}

	return nil
}

func updateSetClause(form url.Values, fields []string) (query string, args []interface{}) {
	stringBuilder := util.NewBuffer()

	for _, field := range fields {
		if _, ok := form[field]; !ok {
			continue
		}
		stringBuilder.Append(",").Append(field).Append("=?")
		args = append(args, form.Get(field))
	}

	if stringBuilder.Len() > 0 {
		query = stringBuilder.String()[1:]
	}

	return
}

func (this *User) String() string {
	buffer := util.NewBuffer()
	buffer.Append(this.Username).Append(this.Email).AppendInt(this.Uid).Append(this.Mtime)

	return buffer.String()
}

// 构造分页html(new)
// curPage 当前页码；pageNum 每页记录数；total总记录数；uri 当前uri
func GenPageHtml(curPage, pageNum, total int, uri string) string {
	// 总页数
	pageCount := total / pageNum
	if total%pageNum != 0 {
		pageCount++
	}
	if pageCount < 2 {
		return ""
	}

	needQues := true
	if strings.Contains(uri, "?") {
		needQues = false
	}

	// 显示5页，然后显示...，接着显示最后两页
	stringBuilder := util.NewBuffer()
	// 当前是第一页
	if curPage != 1 {
		stringBuilder.Append(`<li><a href="`).Append(uri)
		if needQues {
			stringBuilder.Append("?")
		} else {
			stringBuilder.Append("&")
		}
		stringBuilder.Append("p=").AppendInt(curPage - 1).Append(`">&laquo;</a>`)
	} else {
		stringBuilder.Append(`<li class="disabled"><a href="#">&laquo;</a>`)
	}
	stringBuilder.Append(`</li>`)

	before := 5
	showPages := 8
	for i := 0; i < pageCount; i++ {
		if i >= showPages {
			break
		}
		if curPage == i+1 {
			stringBuilder.Append(`<li class="active"><a href="`).Append(uri)
			if needQues {
				stringBuilder.Append("?")
			} else {
				stringBuilder.Append("&")
			}

			stringBuilder.Append("p=").AppendInt(i + 1).Append(`">`).AppendInt(i + 1).Append("</a></li>")
			continue
		}
		// 分界点
		if curPage >= before {
			if curPage >= 7 {
				before = 2
			} else {
				before = curPage + 2
			}
			showPages += 2
		}
		if i == before {
			stringBuilder.Append(`<li class="disabled"><a href="#"><span class="gap">…</span></a></li>`)
			continue
		}
		stringBuilder.Append(`<li><a href="`).Append(uri)
		if needQues {
			stringBuilder.Append("?")
		} else {
			stringBuilder.Append("&")
		}
		stringBuilder.Append("p=").AppendInt(i + 1).Append(`">`).AppendInt(i + 1).Append("</a></li>")
	}

	// 最后一页
	if curPage < pageCount {
		stringBuilder.Append(`<li><a href="`).Append(uri)
		if needQues {
			stringBuilder.Append("?")
		} else {
			stringBuilder.Append("&")
		}
		stringBuilder.Append("p=").AppendInt(curPage + 1).Append(`">&raquo;</a>`)
	} else {
		stringBuilder.Append(`<li class="disabled"><a href="#">&raquo;</a>`)
	}
	stringBuilder.Append(`</li>`)

	return stringBuilder.String()
}