From f66f5352a25b77e4a930d39e3ba9c260efedf14b Mon Sep 17 00:00:00 2001
From: midipix <writeonce@midipix.org>
Date: Wed, 17 Jul 2024 05:45:36 +0000
Subject: write mode: implemented generation of the cpio archive format.

---
 src/logic/tpax_queue_vector.c | 130 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 126 insertions(+), 4 deletions(-)

(limited to 'src/logic/tpax_queue_vector.c')

diff --git a/src/logic/tpax_queue_vector.c b/src/logic/tpax_queue_vector.c
index cae4da0..1b10feb 100644
--- a/src/logic/tpax_queue_vector.c
+++ b/src/logic/tpax_queue_vector.c
@@ -53,6 +53,118 @@ tpax_hidden const char * tpax_queue_item_full_path(
 	return pathbuf;
 }
 
+static int tpax_cpio_dirent_compare(const void * a, const void * b)
+{
+	const struct tpax_dirent * direnta;
+	const struct tpax_dirent * direntb;
+
+	direnta = *(const struct tpax_dirent **)a;
+	direntb = *(const struct tpax_dirent **)b;
+
+	return (direnta->stdev == direntb->stdev)
+		? direnta->stino - direntb->stino
+		: direnta->stdev - direntb->stdev;
+}
+
+static int tpax_update_cpio_queue_vector(const struct tpax_driver_ctx * dctx)
+{
+	struct tpax_driver_ctx_impl *   ictx;
+	struct tpax_dirent **           cpiov;
+	struct tpax_dirent **           direntv;
+	struct tpax_dirent *            cdent;
+	dev_t                           stdev;
+	ino_t                           stino;
+	int                             cpdev;
+	int                             cpino;
+	int                             nlink;
+	int                             idx;
+
+	/* driver */
+	ictx = tpax_get_driver_ictx(dctx);
+
+	/* not needed? */
+	if (ictx->nqueued == 0)
+		return 0;
+
+	/* vector copy */
+	direntv = ictx->direntv;
+	cpiov   = ictx->cpiov;
+
+	for (; *direntv; )
+		*cpiov++ = *direntv++;
+
+	/* sort by real st_dev, st_ino */
+	qsort(ictx->cpiov,ictx->nqueued,sizeof(*cpiov),tpax_cpio_dirent_compare);
+
+	/* set the cpio internal c_dev, c_ino, and c_nlink fields (U+1F620) */
+	cpiov = ictx->cpiov;
+	cdent = cpiov[0];
+	cpiov++;
+
+	cpdev = 1;
+	cpino = 1;
+	nlink = 1;
+
+	stdev = cdent->stdev;
+	stino = cdent->stino;
+
+	cdent->cpdev = cpdev;
+	cdent->cpino = cpino;
+	cdent->nlink = nlink;
+
+	for (; *cpiov; ) {
+		cdent = *cpiov;
+
+		if (cdent->srdev > 0777777)
+			return TPAX_CUSTOM_ERROR(
+				dctx,
+				TPAX_ERR_FLOW_ERROR);
+
+		if ((cdent->stdev == stdev) && (cdent->stino == stino)) {
+			nlink++;
+
+		} else if (cdent->stdev > stdev) {
+			if (nlink > 1)
+				for (idx=2; idx<=nlink; idx++)
+					cpiov[-idx]->nlink = nlink;
+
+			cpdev++;
+			cpino = 1;
+			nlink = 1;
+
+			stdev = cdent->stdev;
+			stino = cdent->stino;
+
+			if (cpdev > 0777777)
+				return TPAX_CUSTOM_ERROR(
+					dctx,
+					TPAX_ERR_FLOW_ERROR);
+
+		} else if (cdent->stino > stino) {
+			if (nlink > 1)
+				for (idx=2; idx<=nlink; idx++)
+					cpiov[-idx]->nlink = nlink;
+
+			cpino++;
+			stino = cdent->stino;
+			nlink = 1;
+
+			if (cpino > 0777777)
+				return TPAX_CUSTOM_ERROR(
+					dctx,
+					TPAX_ERR_FLOW_ERROR);
+		}
+
+		cdent->cpdev = cpdev;
+		cdent->cpino = cpino;
+		cdent->nlink = nlink;
+
+		cpiov++;
+	}
+
+	return 0;
+}
+
 tpax_hidden int tpax_update_queue_vector(const struct tpax_driver_ctx * dctx)
 {
 	uintptr_t                       addr;
@@ -67,20 +179,26 @@ tpax_hidden int tpax_update_queue_vector(const struct tpax_driver_ctx * dctx)
 	ictx = tpax_get_driver_ictx(dctx);
 
 	/* vector alloc */
-	if (ictx->direntv)
+	if (ictx->direntv) {
 		free(ictx->direntv);
+		free(ictx->cpiov);
+
+		ictx->direntv = 0;
+		ictx->cpiov   = 0;
+	}
 
 	arrsize = ictx->nqueued + 1;
 
 	if (!(ictx->direntv = calloc(arrsize,sizeof(struct tpax_dirent *))))
 		return TPAX_SYSTEM_ERROR(dctx);
 
-	if (ictx->nqueued == 0)
-		return 0;
+	if (dctx->cctx->drvflags & TPAX_DRIVER_WRITE_FORMAT_CPIO)
+		if (!(ictx->cpiov = calloc(arrsize,sizeof(struct tpax_dirent *))))
+			return TPAX_SYSTEM_ERROR(dctx);
 
 	/* queue vector */
 	dentbuf = tpax_get_driver_dirents(dctx);
-	cdent   = dentbuf->dbuf;
+	cdent   = ictx->nqueued ? dentbuf->dbuf : 0;
 
 	for (direntv=ictx->direntv; cdent; direntv++) {
 		*direntv = cdent;
@@ -97,5 +215,9 @@ tpax_hidden int tpax_update_queue_vector(const struct tpax_driver_ctx * dctx)
 		cdent = cnext;
 	}
 
+	if (dctx->cctx->drvflags & TPAX_DRIVER_WRITE_FORMAT_CPIO)
+		if (tpax_update_cpio_queue_vector(dctx) < 0)
+			return TPAX_NESTED_ERROR(dctx);
+
 	return 0;
 }
-- 
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