Files
dbx/crates/dbx-core/src/csv_export.rs
T

439 lines
15 KiB
Rust

use serde::{Deserialize, Serialize};
use serde_json::Value;
use std::fmt;
use std::fs::File;
use std::io::{BufWriter, Write};
use crate::connection::AppState;
use crate::models::connection::DatabaseType;
use crate::query::{execute_sql_statement_with_options, QueryExecutionOptions};
use crate::sql_dialect::{build_table_data_select_sql, TableDataSelectSqlOptions};
const TABLE_DATA_EXPORT_PAGE_SIZE: usize = 10_000;
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct TableCsvExportOptions {
pub file_path: String,
pub connection_id: String,
pub database: String,
#[serde(default, skip_serializing_if = "Option::is_none")]
pub schema: Option<String>,
pub table_name: String,
#[serde(default)]
pub columns: Vec<String>,
#[serde(default, skip_serializing_if = "Option::is_none")]
pub page_size: Option<usize>,
#[serde(default, skip_serializing_if = "Option::is_none")]
pub timeout_secs: Option<u64>,
}
/// CSV 转义直写目标 buffer:包引号 + 内部 `"` 翻倍。值不含 `"` 时整段拷贝,
/// 不做 replace 分配(逐批流式导出对每个单元格调用,是导出热路径)。
fn push_csv_escaped_content(out: &mut String, value: &str) {
let mut rest = value;
while let Some(pos) = rest.find('"') {
out.push_str(&rest[..=pos]);
out.push('"');
rest = &rest[pos + 1..];
}
out.push_str(rest);
}
pub(crate) fn push_csv_escaped(out: &mut String, value: &str) {
out.push('"');
push_csv_escaped_content(out, value);
out.push('"');
}
struct CsvEscapedWriter<'a>(&'a mut String);
impl fmt::Write for CsvEscapedWriter<'_> {
fn write_str(&mut self, value: &str) -> fmt::Result {
push_csv_escaped_content(self.0, value);
Ok(())
}
}
/// 将表导出 CSV 值直接写入已有 buffer;包括 NULL 在内的值均保留分页导出的带引号旧语义。
pub(crate) fn push_csv_text_value(out: &mut String, value: &Value) {
out.push('"');
match value {
Value::Null => {}
Value::String(value) => push_csv_escaped_content(out, value),
Value::Bool(value) => out.push_str(if *value { "true" } else { "false" }),
Value::Number(value) => {
fmt::write(out, format_args!("{value}")).expect("writing a number into a String cannot fail")
}
// 数组和对象可能包含引号,通过转义 writer 格式化,避免分配中间 JSON 字符串
other => fmt::write(&mut CsvEscapedWriter(out), format_args!("{other}"))
.expect("writing JSON into a String cannot fail"),
}
out.push('"');
}
fn push_csv_value(out: &mut String, value: &Value) {
if value.is_null() {
return;
}
push_csv_text_value(out, value);
}
/// TSV 转义直写:仅含特殊字符时包引号(语义与原 escape_tsv 一致)。
fn push_tsv_escaped(out: &mut String, value: &str) {
if value.contains('\t') || value.contains('\n') || value.contains('\r') || value.contains('"') {
push_csv_escaped(out, value);
} else {
out.push_str(value);
}
}
fn push_tsv_value(out: &mut String, value: &Value) {
match value {
Value::Null => {}
Value::String(v) => push_tsv_escaped(out, v),
Value::Bool(v) => out.push_str(if *v { "true" } else { "false" }),
Value::Number(value) => {
fmt::write(out, format_args!("{value}")).expect("writing a number into a String cannot fail")
}
other => push_tsv_escaped(out, &other.to_string()),
}
}
pub(crate) fn push_tsv_row(out: &mut String, row: &[Value]) {
for (cell_index, cell) in row.iter().enumerate() {
if cell_index > 0 {
out.push('\t');
}
push_tsv_value(out, cell);
}
}
/// 预分配粗估:按全部行的实际单元格数求和(不假设等宽),饱和运算防溢出,
/// 并设上限——估算只是性能提示,绝不能因病态输入放大成巨额分配
const ROWS_CAPACITY_ESTIMATE_MAX: usize = 16 * 1024 * 1024;
pub(crate) fn estimated_rows_capacity(rows: &[Vec<Value>]) -> usize {
let cells: usize = rows.iter().map(Vec::len).fold(0usize, usize::saturating_add);
cells.saturating_mul(12).min(ROWS_CAPACITY_ESTIMATE_MAX)
}
pub(crate) fn escape_csv(value: &str) -> String {
let mut out = String::with_capacity(value.len() + 2);
push_csv_escaped(&mut out, value);
out
}
fn format_csv_value(value: &Value) -> String {
let mut out = String::new();
push_csv_value(&mut out, value);
out
}
#[cfg_attr(not(test), allow(dead_code))]
pub(crate) fn escape_tsv(value: &str) -> String {
let mut out = String::with_capacity(value.len());
push_tsv_escaped(&mut out, value);
out
}
fn push_tsv_rows(out: &mut String, rows: &[Vec<Value>]) {
for (row_index, row) in rows.iter().enumerate() {
if row_index > 0 {
out.push('\n');
}
push_tsv_row(out, row);
}
}
#[cfg_attr(not(test), allow(dead_code))]
pub(crate) fn format_tsv_rows(rows: &[Vec<Value>]) -> String {
let mut out = String::with_capacity(estimated_rows_capacity(rows));
push_tsv_rows(&mut out, rows);
out
}
pub(crate) fn format_tsv(columns: &[String], rows: &[Vec<Value>]) -> String {
let mut out = String::with_capacity(
estimated_rows_capacity(rows).saturating_add(columns.len().saturating_mul(12)).min(ROWS_CAPACITY_ESTIMATE_MAX),
);
for (index, column) in columns.iter().enumerate() {
if index > 0 {
out.push('\t');
}
push_tsv_escaped(&mut out, column);
}
out.push('\n');
push_tsv_rows(&mut out, rows);
out
}
/// Format query-result rows as CSV text without a header row. Database NULLs
/// use the same empty-cell representation as table-data exports. Used by the
/// streaming query-result export for batches after the first.
pub(crate) fn push_query_result_csv_row(out: &mut String, row: &[Value]) {
for (cell_index, cell) in row.iter().enumerate() {
if cell_index > 0 {
out.push(',');
}
push_csv_value(out, cell);
}
}
pub(crate) fn push_table_csv_row(out: &mut String, row: &[Value]) {
for (cell_index, cell) in row.iter().enumerate() {
if cell_index > 0 {
out.push(',');
}
push_csv_text_value(out, cell);
}
}
fn push_query_result_csv_rows(out: &mut String, rows: &[Vec<Value>]) {
for (row_index, row) in rows.iter().enumerate() {
if row_index > 0 {
out.push('\n');
}
push_query_result_csv_row(out, row);
}
}
pub fn format_query_result_csv_rows(rows: &[Vec<Value>]) -> String {
let mut out = String::with_capacity(estimated_rows_capacity(rows));
push_query_result_csv_rows(&mut out, rows);
out
}
fn format_csv_with_value_formatter(columns: &[String], rows: &[Vec<Value>]) -> String {
let mut out = String::with_capacity(
estimated_rows_capacity(rows).saturating_add(columns.len().saturating_mul(12)).min(ROWS_CAPACITY_ESTIMATE_MAX),
);
for (index, column) in columns.iter().enumerate() {
if index > 0 {
out.push(',');
}
push_csv_escaped(&mut out, column);
}
out.push('\n');
push_query_result_csv_rows(&mut out, rows);
out
}
pub fn format_csv(columns: &[String], rows: &[Vec<Value>]) -> String {
format_csv_with_value_formatter(columns, rows)
}
pub fn format_query_result_csv(columns: &[String], rows: &[Vec<Value>]) -> String {
format_csv(columns, rows)
}
fn write_csv_text_row(writer: &mut impl Write, values: impl IntoIterator<Item = String>) -> Result<(), String> {
let mut first = true;
for value in values {
if !first {
writer.write_all(b",").map_err(|err| err.to_string())?;
}
first = false;
writer.write_all(escape_csv(&value).as_bytes()).map_err(|err| err.to_string())?;
}
Ok(())
}
fn write_csv_value_row(writer: &mut impl Write, values: impl IntoIterator<Item = Value>) -> Result<(), String> {
let mut first = true;
for value in values {
if !first {
writer.write_all(b",").map_err(|err| err.to_string())?;
}
first = false;
writer.write_all(format_csv_value(&value).as_bytes()).map_err(|err| err.to_string())?;
}
Ok(())
}
async fn connection_database_type(state: &AppState, connection_id: &str) -> Result<DatabaseType, String> {
state
.configs
.read()
.await
.get(connection_id)
.map(|config| config.db_type)
.ok_or_else(|| format!("Connection config not found: {connection_id}"))
}
pub async fn export_table_data_csv_core(state: &AppState, options: TableCsvExportOptions) -> Result<u64, String> {
let database_type = connection_database_type(state, &options.connection_id).await?;
let page_size = options.page_size.unwrap_or(TABLE_DATA_EXPORT_PAGE_SIZE).max(1);
let mut writer =
BufWriter::new(File::create(&options.file_path).map_err(|err| format!("Failed to write CSV file: {err}"))?);
writer.write_all("\u{FEFF}".as_bytes()).map_err(|err| err.to_string())?;
let mut offset = 0usize;
let mut rows_exported = 0u64;
let mut wrote_header = false;
loop {
let sql = build_table_data_select_sql(TableDataSelectSqlOptions {
database_type: Some(database_type),
schema: options.schema.clone(),
table_name: options.table_name.clone(),
table_type: None,
primary_keys: Vec::new(),
columns: options.columns.clone(),
fallback_order_columns: Vec::new(),
order_by: None,
limit: Some(page_size),
offset: Some(offset),
where_input: None,
include_row_id: false,
..Default::default()
});
let result = execute_sql_statement_with_options(
state,
&options.connection_id,
&options.database,
&sql,
options.schema.as_deref(),
None,
QueryExecutionOptions {
max_rows: Some(page_size),
timeout_secs: options.timeout_secs,
..Default::default()
},
)
.await?;
if !wrote_header {
write_csv_text_row(&mut writer, result.columns)?;
wrote_header = true;
}
let fetched = result.rows.len();
if fetched == 0 {
break;
}
for row in result.rows {
writer.write_all(b"\n").map_err(|err| err.to_string())?;
write_csv_value_row(&mut writer, row)?;
}
rows_exported += fetched as u64;
if fetched < page_size {
break;
}
offset += fetched;
}
if rows_exported == 0 {
writer.write_all(b"\n").map_err(|err| err.to_string())?;
}
writer.flush().map_err(|err| err.to_string())?;
Ok(rows_exported)
}
#[cfg(test)]
mod tests {
use super::{format_csv, format_query_result_csv, format_query_result_csv_rows, format_tsv};
use serde_json::json;
#[test]
fn formats_csv_with_header_and_escaped_values() {
let out = format_csv(&["id".to_string(), "name".to_string()], &[vec![json!(1), json!("Ada \"Lovelace\"")]]);
assert_eq!(out, "\"id\",\"name\"\n\"1\",\"Ada \"\"Lovelace\"\"\"");
}
#[test]
fn formats_null_as_empty_cell() {
let out = format_csv(&["id".to_string(), "note".to_string()], &[vec![json!(1), Value::Null]]);
assert_eq!(out, "\"id\",\"note\"\n\"1\",");
}
#[test]
fn formats_query_result_null_as_empty_cell() {
let out = format_query_result_csv(&["id".to_string(), "note".to_string()], &[vec![json!(1), Value::Null]]);
assert_eq!(out, "\"id\",\"note\"\n\"1\",");
}
#[test]
fn formats_streamed_query_result_null_as_empty_cell_and_preserves_literal_null() {
let out = format_query_result_csv_rows(&[vec![Value::Null, json!("NULL"), json!("")]]);
assert_eq!(out, ",\"NULL\",\"\"");
}
#[test]
fn formats_tsv_with_empty_null_and_escaped_special_values() {
let out = format_tsv(
&["id".to_string(), "note".to_string()],
&[vec![json!(1), Value::Null], vec![json!(2), json!("line1\n\"line2\"")]],
);
assert_eq!(out, "id\tnote\n1\t\n2\t\"line1\n\"\"line2\"\"\"");
}
#[test]
fn capacity_estimate_sums_actual_cells_across_ragged_rows() {
// 不等宽行按实际单元格数求和,不得按首行宽度放大
let wide_first = vec![vec![serde_json::Value::Null; 1000], vec![], vec![serde_json::Value::Null]];
assert_eq!(super::estimated_rows_capacity(&wide_first), 1001 * 12);
assert!(super::estimated_rows_capacity(&[]) == 0);
}
#[test]
fn escape_tsv_matches_reference_semantics() {
// TSV 仅在含 \t/\n/\r/引号时包引号;逗号不触发
for input in ["", "plain", "with,comma", "tab\there", "line\nbreak", "cr\rhere", "quo\"te", "\t\"mix\""] {
let expected =
if input.contains('\t') || input.contains('\n') || input.contains('\r') || input.contains('"') {
format!("\"{}\"", input.replace('"', "\"\""))
} else {
input.to_string()
};
assert_eq!(super::escape_tsv(input), expected, "input: {input:?}");
}
}
#[test]
fn push_csv_escaped_matches_replace_reference() {
// 直写实现必须与原 replace 版本逐字节等价(含引号在首/尾/连续的边界)
for input in ["", "plain", "\"", "\"\"", "a\"b", "\"start", "end\"", "mid\"\"dle", "逗,号\n换行"] {
let expected = format!("\"{}\"", input.replace('"', "\"\""));
assert_eq!(super::escape_csv(input), expected, "input: {input:?}");
}
}
#[test]
fn push_csv_text_value_preserves_paginated_export_semantics() {
let cases = [
(serde_json::Value::Null, "\"\""),
(serde_json::json!(true), "\"true\""),
(serde_json::json!(42.5), "\"42.5\""),
(serde_json::json!("a\"b"), "\"a\"\"b\""),
(serde_json::json!({"key": "value"}), "\"{\"\"key\"\":\"\"value\"\"}\""),
];
for (value, expected) in cases {
let mut out = String::from("prefix,");
super::push_csv_text_value(&mut out, &value);
assert_eq!(out, format!("prefix,{expected}"));
}
}
#[test]
fn reusable_row_buffers_match_batch_formatters() {
let row = vec![Value::Null, json!("NULL"), json!("line\n\"two\""), json!(42)];
let mut csv = String::new();
super::push_query_result_csv_row(&mut csv, &row);
assert_eq!(csv, super::format_query_result_csv_rows(std::slice::from_ref(&row)));
let mut table_csv = String::new();
super::push_table_csv_row(&mut table_csv, &row);
assert_eq!(table_csv, "\"\",\"NULL\",\"line\n\"\"two\"\"\",\"42\"");
let mut tsv = String::new();
super::push_tsv_row(&mut tsv, &row);
assert_eq!(tsv, super::format_tsv_rows(&[row]));
}
use serde_json::Value;
}