1 files changed, 139 insertions, 0 deletions
diff --git a/src/driver/tbnf_unit_ctx.c b/src/driver/tbnf_unit_ctx.c
new file mode 100644
index 0000000..fedcbaa
--- /dev/null
+++ b/src/driver/tbnf_unit_ctx.c
@@ -0,0 +1,139 @@
+/**************************************************************/
+/*  treebnf: a tree oriented bnf library                      */
+/*  Copyright (C) 2024  SysDeer Technologies, LLC             */
+/*  Released under GPLv2 and GPLv3; see COPYING.TREEBNF.      */
+/**************************************************************/
+
+#include <stdint.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+
+#include <treebnf/treebnf.h>
+#include "treebnf_driver_impl.h"
+#include "treebnf_errinfo_impl.h"
+#include "treebnf_tmpfile_impl.h"
+
+static int tbnf_free_unit_ctx_impl(struct tbnf_unit_ctx_impl * ctx, int ret)
+{
+	if (ctx) {
+		tbnf_lib_unmap_raw_input(&ctx->map);
+		free(ctx);
+	}
+
+	return ret;
+}
+
+static int tbnf_stdin_to_tmp(const struct tbnf_driver_ctx * dctx)
+{
+	struct tbnf_driver_ctx_impl *	ictx;
+	int				fdtmp;
+
+	ssize_t ret;
+	ssize_t cnt;
+	char *	ch;
+	char	buf[4096];
+
+	ictx = tbnf_get_driver_ictx(dctx);
+
+	if (ictx->fdtmpin >= 0)
+		return dup(ictx->fdtmpin);
+
+	if ((fdtmp = tbnf_tmpfile()) < 0)
+		return -1;
+
+	if ((ictx->fdtmpin = dup(fdtmp)) < 0) {
+		close(fdtmp);
+		return -1;
+	}
+
+	for (;;) {
+		ret = read(0,buf,sizeof(buf)-1);
+
+		while ((ret < 0) && (errno == EINTR))
+			ret = read(0,buf,sizeof(buf)-1);
+
+		if (ret < 0) {
+			close(fdtmp);
+			return -1;
+
+		} else if (ret == 0) {
+			return fdtmp;
+
+		} else {
+			ch  = buf;
+			cnt = ret;
+
+			for (; cnt; ) {
+				ret = write(fdtmp,ch,cnt);
+
+				while ((ret < 0) && (errno == EINTR))
+					ret = write(fdtmp,ch,cnt);
+
+				if (ret < 0) {
+					close(fdtmp);
+					return -1;
+				}
+
+				ch  += ret;
+				cnt -= ret;
+			}
+		}
+	}
+}
+
+int tbnf_lib_get_unit_ctx(
+	const struct tbnf_driver_ctx *	dctx,
+	const char *			path,
+	struct tbnf_unit_ctx **		pctx)
+{
+	struct tbnf_unit_ctx_impl *	ctx;
+	int				prot;
+	int                             fd;
+
+	if (!dctx)
+		return TBNF_CUSTOM_ERROR(
+			dctx,TBNF_ERR_NULL_CONTEXT);
+
+	else if (!(ctx = calloc(1,sizeof(*ctx))))
+		return TBNF_BUFFER_ERROR(dctx);
+
+	tbnf_driver_set_ectx(
+		dctx,0,path);
+
+	prot = PROT_READ;
+
+	if (strcmp(path,"-"))
+		fd = -1;
+
+	else if ((fd = tbnf_stdin_to_tmp(dctx)) < 0)
+		return tbnf_free_unit_ctx_impl(
+			ctx,TBNF_FILE_ERROR(dctx));
+
+	if (tbnf_lib_map_raw_input(dctx,fd,path,prot,&ctx->map))
+		return tbnf_free_unit_ctx_impl(
+			ctx,TBNF_NESTED_ERROR(dctx));
+
+	if (fd >= 0)
+		close(fd);
+
+	ctx->path	= path;
+	ctx->uctx.path	= &ctx->path;
+	ctx->uctx.map	= &ctx->map;
+
+	*pctx = &ctx->uctx;
+	return 0;
+}
+
+void tbnf_lib_free_unit_ctx(struct tbnf_unit_ctx * ctx)
+{
+	struct tbnf_unit_ctx_impl *	ictx;
+	uintptr_t			addr;
+
+	if (ctx) {
+		addr = (uintptr_t)ctx - offsetof(struct tbnf_unit_ctx_impl,uctx);
+		ictx = (struct tbnf_unit_ctx_impl *)addr;
+		tbnf_free_unit_ctx_impl(ictx,0);
+	}
+}