feat(profiling): keep string cache data alive longer (#2668)

We still have to re-establish the link in the run time cache, but the
string set itself will keep the sets and data alive.

---------

Co-authored-by: Florian Engelhardt <[email protected]>

Author: morrisonlevi

Cargo.lock

@@ -15,12 +15,11 @@ bench = false # disables cargo build in libtest bench
 # Avoid ahash 0.8.7 we run into https://github.com/tkaitchuck/aHash/issues/195.
 ahash = { version = "0.8.11" }
 anyhow = { version = "1.0" }
-# v3.15 bumps MSRV to Rust 1.73
-bumpalo = { version = "=3.14.0", features = ["collections"] }
 cfg-if = { version = "1.0" }
 cpu-time = { version = "1.0" }
 chrono = { version = "0.4" }
 crossbeam-channel = { version = "0.5", default-features = false, features = ["std"] }
+datadog-alloc = { git = "https://github.com/DataDog/libdatadog", tag = "v10.0.0" }
 datadog-profiling = { git = "https://github.com/DataDog/libdatadog", tag = "v10.0.0" }
 ddcommon = { git = "https://github.com/DataDog/libdatadog", tag = "v10.0.0" }
 env_logger = { version = "0.11", default-features = false }
@@ -30,10 +29,10 @@ libc = "0.2"
 # TRACE set to max to support runtime configuration.
 log = { version = "0.4", features = ["max_level_trace", "release_max_level_trace"]}
 once_cell = { version = "1.12" }
-ouroboros = { version = "0.18" }
 serde_json = {version = "1.0"}
 rand = { version = "0.8.5" }
 rand_distr = { version = "0.4.3" }
+rustc-hash = "1.1.0"
 uuid = { version = "1.0", features = ["v4"] }
 
 [dev-dependencies]

profiling/.cargo/config renamed to profiling/.cargo/config.toml

@@ -6,9 +6,11 @@ mod logging;
 mod pcntl;
 pub mod profiling;
 mod sapi;
+mod thin_str;
+mod wall_time;
 
 #[cfg(php_run_time_cache)]
-mod string_table;
+mod string_set;
 
 #[cfg(feature = "allocation_profiling")]
 mod allocation;
@@ -19,8 +21,6 @@ mod exception;
 #[cfg(feature = "timeline")]
 mod timeline;
 
-mod wall_time;
-
 use crate::config::{SystemSettings, INITIAL_SYSTEM_SETTINGS};
 use bindings::{
     self as zend, ddog_php_prof_php_version, ddog_php_prof_php_version_id, ZendExtension,

profiling/Cargo.toml

@@ -515,6 +515,9 @@ pub enum UploadMessage {
     Upload(Box<UploadRequest>),
 }
 
+#[cfg(feature = "timeline")]
+const COW_EVAL: Cow<str> = Cow::Borrowed("[eval]");
+
 impl Profiler {
     pub fn new(system_settings: &SystemSettings) -> Self {
         let fork_barrier = Arc::new(Barrier::new(3));