[wip] plugin stuff

1 files changed, 63 insertions, 0 deletions

diff --git a/include/pipeline.h b/include/pipeline.h
new file mode 100644
index 0000000..d662b09
--- /dev/null
+++ b/include/pipeline.h
@@ -0,0 +1,63 @@
+#ifndef PTXMC_PIPELINE_H_INCLUDED
+#define PTXMC_PIPELINE_H_INCLUDED
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdarg.h>
+
+#include "config.h"
+
+#define PIPELINE_STAGE ATTR_WUR ATTR_ACCESS((read_only, 1))
+#define PIPELINE_INIT ATTR_ACCESS((read_only, 1))
+#define PIPELINE_CLEANUP ATTR_ACCESS((read_only, 1))
+
+typedef struct ptx__pipeline_ctx_tag ptx_pipeline_ctx_t;
+typedef struct ptx__pipeline_tag ptx_pipeline_t;
+
+typedef int (ptx_pipeline_proc_t)(const ptx_pipeline_ctx_t * /*ctx*/, const void * /*data*/, size_t /*len*/) PIPELINE_STAGE;
+typedef int (ptx_pipeline_init_proc_t)(const char * /*name*/, void ** /*ppuser*/, va_list /*init_args*/) PIPELINE_INIT;
+typedef void (ptx_pipeline_cleanup_proc_t)(const char * /*name*/, void * /*puser*/) PIPELINE_CLEANUP;
+
+struct ptx_pipeline_stage_funcs {
+  ptx_pipeline_proc_t *handler;
+  ptx_pipeline_init_proc_t *init;
+  ptx_pipeline_cleanup_proc_t *cleanup;
+};
+
+#ifdef MODULE
+#define MODEXP extern
+#else
+#define MODEXP \
+__attribute__((visibility("protected")))
+#endif
+
+/* allocates a new pipeline, with space for `initial_size' new stages. */
+MODEXP ptx_pipeline_t *ptx_pipeline_new(size_t initial_size) ATTR_WUR ATTR_MALLOC() ATTR_MALLOC((ptx_pipeline_free, 1));
+
+/* frees an existing pipeline stage. note that this will call the cleanup function in the stages as well. */
+void ptx_pipeline_free(ptx_pipeline_t *pl);
+
+/* adds `stage' with `name' to `pipeline' after `after'
+ * returns: number of stages added to pipeline (0 or 1), or -1 if there was an allocation or initialization error. */
+int ptx_pipeline_add_after(ptx_pipeline_t *pipeline, const struct ptx_pipeline_stage_funcs *stage, const char *name, const char *after, ...);
+/* adds `stage' with `name' to `pipeline' before `before'
+ * returns: number of stages added to pipeline (0 or 1), or -1 if there was an allocation or initialization error. */
+int ptx_pipeline_add_before(ptx_pipeline_t *pipeline, const struct ptx_pipeline_stage_funcs *stage, const char *name, const char *before, ...);
+
+/* TODO: could theoretically have versions of the above functions that don't defensively copy `name' */
+
+/* returns: number of stages removed from pipeline */
+int ptx_pipeline_remove_stage(ptx_pipeline_t *pipeline, const char *name);
+
+/* this pointer is guaranteed to be valid as long as the pipeline context is active (i.e., within this handler function)
+ * If you need to access user data of a stage from outside of a handler function, TODO */
+void **ptx_pipeline_ctx_get_user(const ptx_pipeline_ctx_t *ctx);
+const char *ptx_pipeline_ctx_get_name(const ptx_pipeline_ctx_t *ctx);
+
+int ptx_pipeline_ctx_next(const ptx_pipeline_ctx_t *ctx, const void *nextdata, size_t nextsize);
+
+void ptx_pipeline_ctx_diag(const ptx_pipeline_ctx_t *ctx, int lvl, const char *fmt, ...) ATTR_FORMAT((printf, 3, 4)); /* TODO: pipeline stages should be able to send diagnostic messages */
+
+int ptx_pipeline_handle(ptx_pipeline_t *pipeline, const void *data, size_t sz); /* TODO: diagnostic */
+
+#endif /* include guard */