driver: added slbt_lib_get_txtfile_ctx(): plain line vector from a text file.

1 files changed, 153 insertions, 0 deletions

diff --git a/src/driver/slbt_txtfile_ctx.c b/src/driver/slbt_txtfile_ctx.c
new file mode 100644
index 0000000..12b9cff
--- /dev/null
+++ b/src/driver/slbt_txtfile_ctx.c
@@ -0,0 +1,153 @@
+/*******************************************************************/
+/*  slibtool: a skinny libtool implementation, written in C        */
+/*  Copyright (C) 2016--2024  SysDeer Technologies, LLC            */
+/*  Released under the Standard MIT License; see COPYING.SLIBTOOL. */
+/*******************************************************************/
+
+#include <ctype.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+
+#include <slibtool/slibtool.h>
+#include "slibtool_driver_impl.h"
+#include "slibtool_errinfo_impl.h"
+
+/********************************************************/
+/* Read a text file, and create an in-memory vecotr of  */
+/* normalized text lines, stripped of both leading and  */
+/* trailing white space.                                */
+/********************************************************/
+
+static int slbt_lib_free_txtfile_ctx_impl(
+	struct slbt_txtfile_ctx_impl *  ctx,
+	struct slbt_input *             mapinfo,
+	int                             ret)
+{
+	if (mapinfo)
+		slbt_fs_unmap_input(mapinfo);
+
+	if (ctx) {
+		if (ctx->pathbuf)
+			free(ctx->pathbuf);
+
+		if (ctx->txtlines)
+			free(ctx->txtlines);
+
+		if (ctx->txtlinev)
+			free(ctx->txtlinev);
+
+		free(ctx);
+	}
+
+	return ret;
+}
+
+int slbt_lib_get_txtfile_ctx(
+	const struct slbt_driver_ctx *  dctx,
+	const char *                    path,
+	struct slbt_txtfile_ctx **      pctx)
+{
+	struct slbt_txtfile_ctx_impl *  ctx;
+	struct slbt_input               mapinfo;
+	size_t                          nlines;
+	char *                          ch;
+	char *                          cap;
+	char *                          src;
+	char *                          mark;
+	const char **                   pline;
+	char                            dummy;
+	int                             cint;
+
+	/* map txtfile file temporarily */
+	if (slbt_fs_map_input(dctx,-1,path,PROT_READ,&mapinfo) < 0)
+		return SLBT_NESTED_ERROR(dctx);
+
+	/* alloc context */
+	if (!(ctx = calloc(1,sizeof(*ctx))))
+		return slbt_lib_free_txtfile_ctx_impl(
+			ctx,&mapinfo,
+			SLBT_BUFFER_ERROR(dctx));
+
+	/* count lines */
+	src = mapinfo.size ? mapinfo.addr : &dummy;
+	cap = &src[mapinfo.size];
+
+	for (; (src<cap) && isspace((cint=*src)); )
+		src++;
+
+	for (ch=src,nlines=0; ch<cap; ch++)
+		nlines += (*ch == '\n');
+
+	nlines += (ch[-1] != '\n');
+
+	/* clone path, alloc string buffer and line vector */
+	if (!(ctx->pathbuf = strdup(path)))
+		return slbt_lib_free_txtfile_ctx_impl(
+			ctx,&mapinfo,
+			SLBT_SYSTEM_ERROR(dctx,0));
+
+	if (!(ctx->txtlines = calloc(mapinfo.size+1,1)))
+		return slbt_lib_free_txtfile_ctx_impl(
+			ctx,&mapinfo,
+			SLBT_SYSTEM_ERROR(dctx,0));
+
+	if (!(ctx->txtlinev = calloc(nlines+1,sizeof(char *))))
+		return slbt_lib_free_txtfile_ctx_impl(
+			ctx,&mapinfo,
+			SLBT_SYSTEM_ERROR(dctx,0));
+
+	/* copy the source to the allocated string buffer */
+	memcpy(ctx->txtlines,mapinfo.addr,mapinfo.size);
+	slbt_fs_unmap_input(&mapinfo);
+
+	/* populate the line vector, handle whitespace */
+	src = ctx->txtlines;
+	cap = &src[mapinfo.size];
+
+	for (; (src<cap) && isspace((cint=*src)); )
+		*src++ = '\0';
+
+	for (ch=src,pline=ctx->txtlinev; ch<cap; pline++) {
+		for (; (ch<cap) && isspace((cint = *ch)); )
+			ch++;
+
+		if (ch < cap)
+			*pline = ch;
+
+		for (; (ch<cap) && (*ch != '\n'); )
+			ch++;
+
+		mark = ch;
+
+		for (--ch; (ch > *pline) && isspace((cint = *ch)); ch--)
+			*ch = '\0';
+
+		if ((ch = mark) < cap)
+			*ch++ = '\0';
+	}
+
+	/* all done */
+	ctx->dctx         = dctx;
+	ctx->path         = ctx->pathbuf;
+	ctx->tctx.path	  = &ctx->path;
+	ctx->tctx.txtlinev = ctx->txtlinev;
+
+	*pctx = &ctx->tctx;
+
+	return 0;
+}
+
+void slbt_lib_free_txtfile_ctx(struct slbt_txtfile_ctx * ctx)
+{
+	struct slbt_txtfile_ctx_impl *	ictx;
+	uintptr_t			addr;
+
+	if (ctx) {
+		addr = (uintptr_t)ctx - offsetof(struct slbt_txtfile_ctx_impl,tctx);
+		ictx = (struct slbt_txtfile_ctx_impl *)addr;
+		slbt_lib_free_txtfile_ctx_impl(ictx,0,0);
+	}
+}