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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 14:47:53 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 14:47:53 +0000
commitc8bae7493d2f2910b57f13ded012e86bdcfb0532 (patch)
tree24e09d9f84dec336720cf393e156089ca2835791 /ewah/ewah_io.c
parentInitial commit. (diff)
downloadgit-c8bae7493d2f2910b57f13ded012e86bdcfb0532.tar.xz
git-c8bae7493d2f2910b57f13ded012e86bdcfb0532.zip
Adding upstream version 1:2.39.2.upstream/1%2.39.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'ewah/ewah_io.c')
-rw-r--r--ewah/ewah_io.c134
1 files changed, 134 insertions, 0 deletions
diff --git a/ewah/ewah_io.c b/ewah/ewah_io.c
new file mode 100644
index 0000000..9035ee6
--- /dev/null
+++ b/ewah/ewah_io.c
@@ -0,0 +1,134 @@
+/**
+ * Copyright 2013, GitHub, Inc
+ * Copyright 2009-2013, Daniel Lemire, Cliff Moon,
+ * David McIntosh, Robert Becho, Google Inc. and Veronika Zenz
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+#include "git-compat-util.h"
+#include "ewok.h"
+#include "strbuf.h"
+
+int ewah_serialize_to(struct ewah_bitmap *self,
+ int (*write_fun)(void *, const void *, size_t),
+ void *data)
+{
+ size_t i;
+ eword_t dump[2048];
+ const size_t words_per_dump = sizeof(dump) / sizeof(eword_t);
+ uint32_t bitsize, word_count, rlw_pos;
+
+ const eword_t *buffer;
+ size_t words_left;
+
+ /* 32 bit -- bit size for the map */
+ bitsize = htonl((uint32_t)self->bit_size);
+ if (write_fun(data, &bitsize, 4) != 4)
+ return -1;
+
+ /** 32 bit -- number of compressed 64-bit words */
+ word_count = htonl((uint32_t)self->buffer_size);
+ if (write_fun(data, &word_count, 4) != 4)
+ return -1;
+
+ /** 64 bit x N -- compressed words */
+ buffer = self->buffer;
+ words_left = self->buffer_size;
+
+ while (words_left >= words_per_dump) {
+ for (i = 0; i < words_per_dump; ++i, ++buffer)
+ dump[i] = htonll(*buffer);
+
+ if (write_fun(data, dump, sizeof(dump)) != sizeof(dump))
+ return -1;
+
+ words_left -= words_per_dump;
+ }
+
+ if (words_left) {
+ for (i = 0; i < words_left; ++i, ++buffer)
+ dump[i] = htonll(*buffer);
+
+ if (write_fun(data, dump, words_left * 8) != words_left * 8)
+ return -1;
+ }
+
+ /** 32 bit -- position for the RLW */
+ rlw_pos = (uint8_t*)self->rlw - (uint8_t *)self->buffer;
+ rlw_pos = htonl(rlw_pos / sizeof(eword_t));
+
+ if (write_fun(data, &rlw_pos, 4) != 4)
+ return -1;
+
+ return (3 * 4) + (self->buffer_size * 8);
+}
+
+static int write_strbuf(void *user_data, const void *data, size_t len)
+{
+ struct strbuf *sb = user_data;
+ strbuf_add(sb, data, len);
+ return len;
+}
+
+int ewah_serialize_strbuf(struct ewah_bitmap *self, struct strbuf *sb)
+{
+ return ewah_serialize_to(self, write_strbuf, sb);
+}
+
+ssize_t ewah_read_mmap(struct ewah_bitmap *self, const void *map, size_t len)
+{
+ const uint8_t *ptr = map;
+ size_t data_len;
+ size_t i;
+
+ if (len < sizeof(uint32_t))
+ return error("corrupt ewah bitmap: eof before bit size");
+ self->bit_size = get_be32(ptr);
+ ptr += sizeof(uint32_t);
+ len -= sizeof(uint32_t);
+
+ if (len < sizeof(uint32_t))
+ return error("corrupt ewah bitmap: eof before length");
+ self->buffer_size = self->alloc_size = get_be32(ptr);
+ ptr += sizeof(uint32_t);
+ len -= sizeof(uint32_t);
+
+ REALLOC_ARRAY(self->buffer, self->alloc_size);
+
+ /*
+ * Copy the raw data for the bitmap as a whole chunk;
+ * if we're in a little-endian platform, we'll perform
+ * the endianness conversion in a separate pass to ensure
+ * we're loading 8-byte aligned words.
+ */
+ data_len = st_mult(self->buffer_size, sizeof(eword_t));
+ if (len < data_len)
+ return error("corrupt ewah bitmap: eof in data "
+ "(%"PRIuMAX" bytes short)",
+ (uintmax_t)(data_len - len));
+ memcpy(self->buffer, ptr, data_len);
+ ptr += data_len;
+ len -= data_len;
+
+ for (i = 0; i < self->buffer_size; ++i)
+ self->buffer[i] = ntohll(self->buffer[i]);
+
+ if (len < sizeof(uint32_t))
+ return error("corrupt ewah bitmap: eof before rlw");
+ self->rlw = self->buffer + get_be32(ptr);
+ ptr += sizeof(uint32_t);
+ len -= sizeof(uint32_t);
+
+ return ptr - (const uint8_t *)map;
+}