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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 03:10:08 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 03:10:08 +0000
commit5262a872f308b3b584c97d621992fb3877e392b8 (patch)
treeb956c322376141abeafe639bd72cfecdf16954b5 /src/liblzma/common/vli_encoder.c
parentInitial commit. (diff)
downloadxz-utils-5262a872f308b3b584c97d621992fb3877e392b8.tar.xz
xz-utils-5262a872f308b3b584c97d621992fb3877e392b8.zip
Adding upstream version 5.6.1+really5.4.5.upstream/5.6.1+really5.4.5
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/liblzma/common/vli_encoder.c')
-rw-r--r--src/liblzma/common/vli_encoder.c69
1 files changed, 69 insertions, 0 deletions
diff --git a/src/liblzma/common/vli_encoder.c b/src/liblzma/common/vli_encoder.c
new file mode 100644
index 0000000..f864269
--- /dev/null
+++ b/src/liblzma/common/vli_encoder.c
@@ -0,0 +1,69 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file vli_encoder.c
+/// \brief Encodes variable-length integers
+//
+// Author: Lasse Collin
+//
+// This file has been put into the public domain.
+// You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "common.h"
+
+
+extern LZMA_API(lzma_ret)
+lzma_vli_encode(lzma_vli vli, size_t *vli_pos,
+ uint8_t *restrict out, size_t *restrict out_pos,
+ size_t out_size)
+{
+ // If we haven't been given vli_pos, work in single-call mode.
+ size_t vli_pos_internal = 0;
+ if (vli_pos == NULL) {
+ vli_pos = &vli_pos_internal;
+
+ // In single-call mode, we expect that the caller has
+ // reserved enough output space.
+ if (*out_pos >= out_size)
+ return LZMA_PROG_ERROR;
+ } else {
+ // This never happens when we are called by liblzma, but
+ // may happen if called directly from an application.
+ if (*out_pos >= out_size)
+ return LZMA_BUF_ERROR;
+ }
+
+ // Validate the arguments.
+ if (*vli_pos >= LZMA_VLI_BYTES_MAX || vli > LZMA_VLI_MAX)
+ return LZMA_PROG_ERROR;
+
+ // Shift vli so that the next bits to encode are the lowest. In
+ // single-call mode this never changes vli since *vli_pos is zero.
+ vli >>= *vli_pos * 7;
+
+ // Write the non-last bytes in a loop.
+ while (vli >= 0x80) {
+ // We don't need *vli_pos during this function call anymore,
+ // but update it here so that it is ready if we need to
+ // return before the whole integer has been decoded.
+ ++*vli_pos;
+ assert(*vli_pos < LZMA_VLI_BYTES_MAX);
+
+ // Write the next byte.
+ out[*out_pos] = (uint8_t)(vli) | 0x80;
+ vli >>= 7;
+
+ if (++*out_pos == out_size)
+ return vli_pos == &vli_pos_internal
+ ? LZMA_PROG_ERROR : LZMA_OK;
+ }
+
+ // Write the last byte.
+ out[*out_pos] = (uint8_t)(vli);
+ ++*out_pos;
+ ++*vli_pos;
+
+ return vli_pos == &vli_pos_internal ? LZMA_OK : LZMA_STREAM_END;
+
+}