68 lines
1.4 KiB
C
68 lines
1.4 KiB
C
/*
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* sgen-entry-stream.c: EntryStream implementation
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*
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* Copyright (C) 2016 Xamarin Inc
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*
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* Licensed under the MIT license. See LICENSE file in the project root for full license information.
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*/
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#include <stdlib.h>
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#include <unistd.h>
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#include <glib.h>
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#include "sgen-entry-stream.h"
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#define BUFFER_SIZE (1 << 20)
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void
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init_stream (EntryStream *stream, int file)
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{
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stream->file = file;
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stream->buffer = g_malloc0 (BUFFER_SIZE);
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stream->end = stream->buffer + BUFFER_SIZE;
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stream->pos = stream->end;
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}
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void
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reset_stream (EntryStream *stream)
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{
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stream->end = stream->buffer + BUFFER_SIZE;
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stream->pos = stream->end;
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lseek (stream->file, 0, SEEK_SET);
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}
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void
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close_stream (EntryStream *stream)
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{
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g_free (stream->buffer);
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}
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gboolean
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refill_stream (EntryStream *in, size_t size)
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{
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size_t remainder = in->end - in->pos;
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ssize_t refilled;
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g_assert (size > 0);
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g_assert (in->pos >= in->buffer);
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if (in->pos + size <= in->end)
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return TRUE;
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memmove (in->buffer, in->pos, remainder);
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in->pos = in->buffer;
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refilled = read (in->file, in->buffer + remainder, BUFFER_SIZE - remainder);
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if (refilled < 0)
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return FALSE;
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g_assert (refilled + remainder <= BUFFER_SIZE);
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in->end = in->buffer + refilled + remainder;
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return in->end - in->buffer >= size;
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}
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ssize_t
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read_stream (EntryStream *stream, void *out, size_t size)
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{
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if (refill_stream (stream, size)) {
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memcpy (out, stream->pos, size);
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stream->pos += size;
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return size;
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}
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return 0;
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}
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