mirror of
https://github.com/cjdelisle/cjdns
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75 lines
2.3 KiB
C
75 lines
2.3 KiB
C
/* vim: set expandtab ts=4 sw=4: */
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/*
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* You may redistribute this program and/or modify it under the terms of
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* the GNU General Public License as published by the Free Software Foundation,
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* either version 3 of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <https://www.gnu.org/licenses/>.
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*/
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#include "io/ArrayReader.h"
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#include "util/Bits.h"
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#include "util/Identity.h"
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struct ArrayReader_context {
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struct Reader generic;
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const char* pointer;
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const char* endPointer;
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Identity
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};
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/** @see Reader->read() */
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static int read(struct Reader* reader, void* readInto, unsigned long length)
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{
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struct ArrayReader_context* context = Identity_check((struct ArrayReader_context*) reader);
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// Prove that it doesn't run off the end of the buffer or roll over.
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if (context->pointer + length > context->endPointer
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|| context->pointer + length < context->pointer)
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{
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return -1;
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}
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if (length == 0) {
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// Allow peaking.
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*((char*)readInto) = *context->pointer;
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return 0;
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}
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Bits_memcpy(readInto, context->pointer, length);
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context->pointer += length;
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reader->bytesRead += length;
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return 0;
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}
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/** @see Reader->skip() */
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static void skip(struct Reader* reader, unsigned long byteCount)
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{
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struct ArrayReader_context* context = Identity_check((struct ArrayReader_context*) reader);
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context->pointer += byteCount;
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reader->bytesRead += byteCount;
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}
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/** @see ArrayReader.h */
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struct Reader* ArrayReader_new(const void* bufferToRead,
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unsigned long length,
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struct Allocator* alloc)
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{
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struct ArrayReader_context* context = Allocator_clone(alloc, (&(struct ArrayReader_context) {
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.generic = {
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.read = read,
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.skip = skip
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},
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.pointer = bufferToRead,
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.endPointer = (char*) bufferToRead + length
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}));
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Identity_set(context);
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return &context->generic;
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}
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