mg2d: add a context variable to control the log level

Simpler to use than overriding the log callback.

API bump.

4 files changed, 14 insertions, 2 deletions

diff --git a/libmg2d.v b/libmg2d.v
index ec37512..96151a5 100644
--- a/libmg2d.v
+++ b/libmg2d.v
@@ -1,4 +1,4 @@
-LIBMG2D_4 {
+LIBMG2D_5 {
     global: mg2d_*;
     local: *;
 };
diff --git a/mg2d.c b/mg2d.c
index 6b94def..886ef27 100644
--- a/mg2d.c
+++ b/mg2d.c
@@ -570,6 +570,8 @@ static int mg_levels_alloc(MG2DContext *ctx, size_t domain_size)
 
 static void log_default_callback(const MG2DContext *ctx, int level, const char *fmt, va_list vl)
 {
+    if (level > ctx->log_level)
+        return;
     vfprintf(stderr, fmt, vl);
 }
 
@@ -623,6 +625,7 @@ MG2DContext *mg2d_solver_alloc(size_t domain_size)
     ctx->nb_relax_pre  = 1;
     ctx->nb_relax_post = 1;
     ctx->log_callback  = log_default_callback;
+    ctx->log_level     = MG2D_LOG_INFO;
     ctx->nb_threads    = 1;
 
     ctx->u          = priv->root->solver->u;
diff --git a/mg2d.h b/mg2d.h
index 834e717..a587a18 100644
--- a/mg2d.h
+++ b/mg2d.h
@@ -168,7 +168,9 @@ typedef struct MG2DContext {
     /**
      * A callback that will be used to print diagnostic messages.
      *
-     * Defaults to fprintf(stderr, ...)
+     * The default implementation prints to stderr.
+     *
+     * May be set to NULL to disable logging.
      */
     void (*log_callback)(const struct MG2DContext *ctx, int level,
                          const char *fmt, va_list);
@@ -272,6 +274,12 @@ typedef struct MG2DContext {
      * Time-stepping factor to use for relaxation.
      */
     double cfl_factor;
+
+    /**
+     * Maximum level of messages printed by the default logging callback. Has no
+     * effect when log_callback is overridden.
+     */
+    enum MG2DLogLevel log_level;
 } MG2DContext;
 
 /**
diff --git a/mg2d_test.c b/mg2d_test.c
index 9b55963..c04e824 100644
--- a/mg2d_test.c
+++ b/mg2d_test.c
@@ -69,6 +69,7 @@ int main(int argc, char **argv)
     ctx->nb_relax_post = 2;
     ctx->tol = TOL;
     ctx->nb_threads = 1;
+    ctx->log_level = MG2D_LOG_VERBOSE;
 
     {
         MG2DBoundary *bnd = ctx->boundaries[MG2D_BOUNDARY_0L];