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vanilla: DB path — prepared statement (async-db) + single-pass HTML escape #878

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vanilla: DB path — prepared statement (async-db) + single-pass HTML escape #878

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45 changes: 40 additions & 5 deletions frameworks/vanilla-epoll/main.v
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Original file line number Diff line number Diff line change
Expand Up @@ -386,7 +386,31 @@ fn (mut sh Shared) fortunes() string {
}

fn escape_html(s string) string {
return s.replace_each(['&', '&amp;', '<', '&lt;', '>', '&gt;', '"', '&quot;', "'", '&apos;'])
// Fast path: most fortune messages contain no special characters, so return
// the original with no allocation instead of replace_each's 5 full-string
// passes (each scanning + reallocating). Only escape when there's something to.
mut needs := false
for c in s {
if c == `&` || c == `<` || c == `>` || c == `"` || c == `'` {
needs = true
break
}
}
if !needs {
return s
}
mut b := strings.new_builder(s.len + 16)
for c in s {
match c {
`&` { b.write_string('&amp;') }
`<` { b.write_string('&lt;') }
`>` { b.write_string('&gt;') }
`"` { b.write_string('&quot;') }
`'` { b.write_string('&apos;') }
else { b.write_u8(c) }
}
}
return b.str()
}

// digits returns the number of decimal digits in a non-negative integer.
Expand All @@ -412,10 +436,21 @@ fn (mut sh Shared) async_db(min i64, max i64, limit i64) string {
lim = 50
}
mut conn := sh.pool.acquire() or { return '{"items":[],"count":0}' }
rows := conn.exec_param_many('SELECT id, name, category, price, quantity, active, tags, rating_score, rating_count FROM items WHERE price BETWEEN \$1 AND \$2 LIMIT \$3',
[min.str(), max.str(), lim.str()]) or {
sh.pool.release(conn)
return '{"items":[],"count":0}'
// Prepared statement: PostgreSQL parses the SQL once per connection instead of
// on every request (exec_param_many re-parses each call). Lazily prepare on the
// connection's first use — prepared statements are per-session and the pool
// reuses sessions, so after warmup every connection serves exec_prepared.
adb_params := [min.str(), max.str(), lim.str()]
rows := conn.exec_prepared('vanilla_async_db', adb_params) or {
conn.prepare('vanilla_async_db', 'SELECT id, name, category, price, quantity, active, tags, rating_score, rating_count FROM items WHERE price BETWEEN \$1 AND \$2 LIMIT \$3',
3) or {
sh.pool.release(conn)
return '{"items":[],"count":0}'
}
conn.exec_prepared('vanilla_async_db', adb_params) or {
sh.pool.release(conn)
return '{"items":[],"count":0}'
}
}
sh.pool.release(conn)
mut items := []DbItem{cap: rows.len}
Expand Down
45 changes: 40 additions & 5 deletions frameworks/vanilla-io_uring/main.v
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -386,7 +386,31 @@ fn (mut sh Shared) fortunes() string {
}

fn escape_html(s string) string {
return s.replace_each(['&', '&amp;', '<', '&lt;', '>', '&gt;', '"', '&quot;', "'", '&apos;'])
// Fast path: most fortune messages contain no special characters, so return
// the original with no allocation instead of replace_each's 5 full-string
// passes (each scanning + reallocating). Only escape when there's something to.
mut needs := false
for c in s {
if c == `&` || c == `<` || c == `>` || c == `"` || c == `'` {
needs = true
break
}
}
if !needs {
return s
}
mut b := strings.new_builder(s.len + 16)
for c in s {
match c {
`&` { b.write_string('&amp;') }
`<` { b.write_string('&lt;') }
`>` { b.write_string('&gt;') }
`"` { b.write_string('&quot;') }
`'` { b.write_string('&apos;') }
else { b.write_u8(c) }
}
}
return b.str()
}

// digits returns the number of decimal digits in a non-negative integer.
Expand All @@ -412,10 +436,21 @@ fn (mut sh Shared) async_db(min i64, max i64, limit i64) string {
lim = 50
}
mut conn := sh.pool.acquire() or { return '{"items":[],"count":0}' }
rows := conn.exec_param_many('SELECT id, name, category, price, quantity, active, tags, rating_score, rating_count FROM items WHERE price BETWEEN \$1 AND \$2 LIMIT \$3',
[min.str(), max.str(), lim.str()]) or {
sh.pool.release(conn)
return '{"items":[],"count":0}'
// Prepared statement: PostgreSQL parses the SQL once per connection instead of
// on every request (exec_param_many re-parses each call). Lazily prepare on the
// connection's first use — prepared statements are per-session and the pool
// reuses sessions, so after warmup every connection serves exec_prepared.
adb_params := [min.str(), max.str(), lim.str()]
rows := conn.exec_prepared('vanilla_async_db', adb_params) or {
conn.prepare('vanilla_async_db', 'SELECT id, name, category, price, quantity, active, tags, rating_score, rating_count FROM items WHERE price BETWEEN \$1 AND \$2 LIMIT \$3',
3) or {
sh.pool.release(conn)
return '{"items":[],"count":0}'
}
conn.exec_prepared('vanilla_async_db', adb_params) or {
sh.pool.release(conn)
return '{"items":[],"count":0}'
}
}
sh.pool.release(conn)
mut items := []DbItem{cap: rows.len}
Expand Down