caliper.log.v1¶

Service id caliper.log.v1 — structured logs into the host console (PLATFORM.md §7.1); fuller semantics arrive at Task 13. This page embeds the header verbatim; the docs build fails if the file moves.

#pragma once
/* caliper.log.v1 — structured logs into the host console (PLATFORM.md §7.1).
 * IMMUTABLE once published: new capability = log_v2, alongside. */
#include <stdint.h>

#define CALIPER_LOG_V1 "caliper.log.v1"

#ifdef __cplusplus
extern "C" {
#endif

typedef enum CaliperLogLevel {
    CALIPER_LOG_DEBUG = 0,
    CALIPER_LOG_INFO  = 1,
    CALIPER_LOG_WARN  = 2,
    CALIPER_LOG_ERROR = 3
} CaliperLogLevel;

typedef struct CaliperLogV1 {
    uint32_t struct_size;
    void (*log)(CaliperLogLevel level, const char* message_utf8); /* pre-formatted */
} CaliperLogV1;

#ifdef __cplusplus
}
#endif

Semantics¶

Pre-formatted lines. message_utf8 is a single, already-formatted UTF-8 line — no printf format string is interpreted, and no trailing newline is required (the host adds one). Do the formatting on the applet side and pass the finished string.
Where it goes today. The host stamps each line with a local HH:MM:SS timestamp and its level tag and writes it to stderr. A dedicated console panel is planned later; the ABI does not change when that lands — the same table keeps working.
Levels. level is one of CALIPER_LOG_DEBUG/INFO/WARN/ERROR; any value outside 0..3 is treated as INFO.
Threading. Unlike caliper.ui.v1, log() may be called from any thread the applet owns (e.g. a background worker). But the CaliperLogV1* table pointer itself must be obtained via get_service(CALIPER_LOG_V1) during initialize() and cached — resolve it on the UI thread, then call it from wherever you need to log.