/*
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* Copyright (C) 2017 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "include/ese/ese.h"
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static inline uint32_t min_u32(uint32_t a, uint32_t b) { return a < b ? a : b; }
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ESE_API uint32_t ese_sg_length(const struct EseSgBuffer *bufs, uint32_t cnt) {
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const struct EseSgBuffer *buf = bufs;
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uint32_t len = 0;
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if (!bufs || cnt == 0) {
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return 0;
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}
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while (buf < bufs + cnt) {
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/* In reality, this is probably corruption or a mistake. */
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if (ESE_UINT32_MAX - len < buf->len) {
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return ESE_UINT32_MAX;
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}
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len += buf->len;
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buf++;
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}
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return len;
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}
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ESE_API uint32_t ese_sg_to_buf(const struct EseSgBuffer *src, uint32_t src_cnt,
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uint32_t start_at, uint32_t length,
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uint8_t *dst) {
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const struct EseSgBuffer *buf = src;
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uint32_t remaining = length;
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if (!src || src_cnt == 0) {
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return 0;
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}
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while (remaining && buf < src + src_cnt) {
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if (start_at > buf->len) {
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start_at -= buf->len;
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buf++;
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continue;
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}
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uint32_t copy_len = min_u32(remaining, buf->len - start_at);
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ese_memcpy(dst, buf->c_base + start_at, copy_len);
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dst += copy_len;
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remaining -= copy_len;
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start_at = 0;
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buf++;
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}
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return length - remaining;
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}
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ESE_API uint32_t ese_sg_from_buf(struct EseSgBuffer *dst, uint32_t dst_cnt,
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uint32_t start_at, uint32_t length,
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const uint8_t *src) {
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const struct EseSgBuffer *buf = dst;
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uint32_t remaining = length;
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if (!dst || dst_cnt == 0) {
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return 0;
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}
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while (remaining && buf < dst + dst_cnt) {
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if (start_at >= buf->len) {
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start_at -= buf->len;
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buf++;
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continue;
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}
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uint32_t copy_len = min_u32(remaining, buf->len - start_at);
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ese_memcpy(buf->base + start_at, src, copy_len);
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src += copy_len;
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remaining -= copy_len;
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start_at = 0;
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buf++;
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}
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return length - remaining;
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}
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