#!/usr/bin/env bash
## detect-memory-litespeed.sh — sibling to detect-memory.sh.
## Computes LSAPI_CHILDREN + extprocessor memSoftLimit/memHardLimit from
## container memory cap. Sourced by entrypoint-litespeed.sh.

## ---- container memory detection (mirrors detect-memory.sh) ----
CONTAINER_MEMORY_BYTES=""

if [ -f /sys/fs/cgroup/memory.max ]; then
  val=$(cat /sys/fs/cgroup/memory.max 2>/dev/null)
  if [ "$val" != "max" ] && [ -n "$val" ]; then
    CONTAINER_MEMORY_BYTES=$val
  fi
fi

if [ -z "$CONTAINER_MEMORY_BYTES" ] && [ -f /sys/fs/cgroup/memory/memory.limit_in_bytes ]; then
  val=$(cat /sys/fs/cgroup/memory/memory.limit_in_bytes 2>/dev/null)
  if [ -n "$val" ] && [ "$val" -lt 8589934592000 ] 2>/dev/null; then
    CONTAINER_MEMORY_BYTES=$val
  fi
fi

if [ -z "$CONTAINER_MEMORY_BYTES" ] && [ -f /proc/meminfo ]; then
  mem_kb=$(awk '/^MemTotal:/ {print $2}' /proc/meminfo)
  if [ -n "$mem_kb" ]; then
    CONTAINER_MEMORY_BYTES=$((mem_kb * 1024))
  fi
fi

if [ -z "$CONTAINER_MEMORY_BYTES" ]; then
  CONTAINER_MEMORY_BYTES=$((512 * 1024 * 1024))
fi

CONTAINER_MEMORY_MB=$((CONTAINER_MEMORY_BYTES / 1024 / 1024))

## ---- budget split (LSAPI workers get the lion's share) ----
OS_RESERVE_MB=50
OLS_RESERVE_MB=40    # OpenLiteSpeed daemon footprint
DEV_OVERHEAD_MB=0
if [ "${environment:-PROD}" = "DEV" ]; then
  DEV_OVERHEAD_MB=125
fi

AVAILABLE_MB=$((CONTAINER_MEMORY_MB - OS_RESERVE_MB - OLS_RESERVE_MB - DEV_OVERHEAD_MB))
if [ "$AVAILABLE_MB" -lt 60 ]; then
  AVAILABLE_MB=60
fi

## ---- LSAPI children (analogous to PHP_FPM_MAX_CHILDREN) ----
## Per the 2026-06-02 cac-litespeed memory-sizing finding (vantagehealth
## OOM-spawn loop at 512 MB cap): each lsphp worker carries ~115 MB
## shmem-rss + ~25 MB anon + ~10 MB file ≈ 130-150 MB real cgroup cost
## per worker on heavy WP workloads. shmem is RSS-accounted per worker
## (vs cac-fpm's COW-shared fork model) so the cost is real per cgroup,
## not just per process.
##
## 115 (the previous default) was set from idle-state measurements and
## ran brain-jar.com into 142 OOM-kills at 1 GiB on 2026-06-02 night —
## the formula computed CHILDREN=8, which left zero headroom once Divi
## page renders started growing worker anon. Bumped to 130 to track the
## active per-worker cost; gives slightly fewer workers but real headroom.
##
## Sub-512 MB containers remain unsafe for dynamic WP on OLS — the floor
## of 2 workers still applies but it'll be cap-marginal. Per-site override
## via FPM_MAX_CHILDREN env var (panel edit-site UI) overrides this for
## sites where the default isn't right for their workload.
LSPHP_WORKER_ESTIMATE_MB=${LSPHP_WORKER_ESTIMATE_MB:-130}

calc_lsapi_children=$((AVAILABLE_MB / LSPHP_WORKER_ESTIMATE_MB))
if [ "$calc_lsapi_children" -lt 2 ]; then
  calc_lsapi_children=2
fi
if [ "$calc_lsapi_children" -gt 50 ]; then
  calc_lsapi_children=50
fi

## Per-site override knobs — site-pool-env.php still passes FPM_MAX_CHILDREN
## for backward compat, so prefer LSAPI_CHILDREN if set, else FPM_MAX_CHILDREN,
## else the calculated value.
LSAPI_CHILDREN=${LSAPI_CHILDREN:-${FPM_MAX_CHILDREN:-$calc_lsapi_children}}

## Per-worker mem limits (RLIMIT_AS) live in httpd_config.tpl now as
## hard-coded 1024M soft / 1500M hard — those values comfortably fit
## typical Divi/WooCommerce VSZ (~280-365 MB) while still catching a
## true runaway script. Cgroup remains the real backstop. The earlier
## AVAILABLE/CHILDREN formula was killing legitimate workers because
## it conflated VSZ (RLIMIT_AS) with RSS-budget arithmetic.

export CONTAINER_MEMORY_MB LSAPI_CHILDREN