Adds buffer based IO support.

src/readstat.h

@@ -343,6 +343,7 @@ typedef struct readstat_parser_s {
 } readstat_parser_t;
 
 readstat_parser_t *readstat_parser_init(void);
+readstat_parser_t *readstat_buffer_parser_init(const char* buf, size_t buf_size);
 void readstat_parser_free(readstat_parser_t *parser);
 void readstat_io_free(readstat_io_t *io);
 

src/readstat_io_buffer.c

@@ -0,0 +1,94 @@
+
+#include <fcntl.h>
+#include <stdlib.h>
+
+#include "readstat.h"
+#include "readstat_io_buffer.h"
+
+int buffer_open_handler(const char *ignored, void *io_ctx) {
+    ((buffer_io_ctx_t*) io_ctx)->pos = 0;
+    return READSTAT_HANDLER_OK;
+}
+
+int buffer_close_handler(void *io_ctx) {
+    ((buffer_io_ctx_t*) io_ctx)->pos = 0;
+    return READSTAT_HANDLER_OK;
+}
+
+readstat_off_t buffer_seek_handler(readstat_off_t offset,
+                                   readstat_io_flags_t whence,
+                                   void *io_ctx) {
+    readstat_off_t new_pos = 0;
+    switch(whence) {
+        case READSTAT_SEEK_SET:
+            new_pos = offset;
+            break;
+        case READSTAT_SEEK_CUR:
+            new_pos = ((buffer_io_ctx_t*) io_ctx)->pos+offset;
+            break;
+        case READSTAT_SEEK_END:
+            new_pos = ((buffer_io_ctx_t*) io_ctx)->size+offset;
+            break;
+        default:
+            return -1;
+    }
+    if(new_pos < 0)
+        return -1;
+
+    ((buffer_io_ctx_t*) io_ctx)->pos = new_pos;
+    return ((buffer_io_ctx_t*) io_ctx)->pos;
+}
+
+ssize_t buffer_read_handler(void *buf, size_t nbyte, void *io_ctx) {
+    buffer_io_ctx_t* buf_ctx = (buffer_io_ctx_t*) io_ctx;
+    ssize_t available = buf_ctx->size - buf_ctx->pos;
+    if((ssize_t)nbyte > available)
+        nbyte = available > 0 ? available : 0;
+    if(nbyte <= 0) 
+        return 0;
+    memcpy(buf, buf_ctx->buf + buf_ctx->pos, nbyte);
+    buf_ctx->pos += nbyte;
+    return nbyte;
+}
+
+readstat_error_t buffer_update_handler(long file_size, 
+        readstat_progress_handler progress_handler, void *user_ctx,
+        void *io_ctx) {
+    if (!progress_handler)
+        return READSTAT_OK;
+
+    if (progress_handler(1.0 * ((buffer_io_ctx_t*) io_ctx)->pos / file_size, user_ctx))
+        return READSTAT_ERROR_USER_ABORT;
+
+    return READSTAT_OK;
+}
+
+readstat_error_t buffer_io_init(readstat_parser_t *parser, const char *buffer, size_t size) {
+    readstat_error_t retval = READSTAT_OK;
+    buffer_io_ctx_t *io_ctx = NULL;
+
+    if ((retval = readstat_set_open_handler(parser, buffer_open_handler)) != READSTAT_OK)
+        return retval;
+
+    if ((retval = readstat_set_close_handler(parser, buffer_close_handler)) != READSTAT_OK)
+        return retval;
+
+    if ((retval = readstat_set_seek_handler(parser, buffer_seek_handler)) != READSTAT_OK)
+        return retval;
+
+    if ((retval = readstat_set_read_handler(parser, buffer_read_handler)) != READSTAT_OK)
+        return retval;
+
+    if ((readstat_set_update_handler(parser, buffer_update_handler)) != READSTAT_OK)
+        return retval;
+
+    io_ctx = calloc(1, sizeof(buffer_io_ctx_t));
+    io_ctx->buf = buffer;
+    io_ctx->size = size;
+    io_ctx->pos = 0;
+
+    retval = readstat_set_io_ctx(parser, (void*) io_ctx);
+    parser->io->io_ctx_needs_free = 1;
+
+    return retval;
+}

src/readstat_io_buffer.h

@@ -0,0 +1,13 @@
+
+typedef struct buffer_io_ctx_s {
+	const char *buf;
+    size_t     size;
+    size_t     pos;
+} buffer_io_ctx_t;
+
+int buffer_open_handler(const char *ignored, void *io_ctx);
+int buffer_close_handler(void *io_ctx);
+readstat_off_t buffer_seek_handler(readstat_off_t offset, readstat_io_flags_t whence, void *io_ctx);
+ssize_t buffer_read_handler(void *buf, size_t nbytes, void *io_ctx);
+readstat_error_t buffer_update_handler(long file_size, readstat_progress_handler progress_handler, void *user_ctx, void *io_ctx);
+readstat_error_t buffer_io_init(readstat_parser_t *parser, const char *buffer, size_t size);

src/readstat_parser.c

@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include "readstat.h"
 #include "readstat_io_unistd.h"
+#include "readstat_io_buffer.h"
 
 readstat_parser_t *readstat_parser_init() {
     readstat_parser_t *parser = calloc(1, sizeof(readstat_parser_t));
@@ -14,6 +15,17 @@ readstat_parser_t *readstat_parser_init() {
     return parser;
 }
 
+readstat_parser_t *readstat_buffer_parser_init(const char* buf, size_t buf_size) {
+    readstat_parser_t *parser = calloc(1, sizeof(readstat_parser_t));
+    parser->io = calloc(1, sizeof(readstat_io_t));
+    if (buffer_io_init(parser, buf, buf_size) != READSTAT_OK) {
+        readstat_parser_free(parser);
+        return NULL;
+    }
+    parser->output_encoding = "UTF-8";
+    return parser;
+}
+
 void readstat_parser_free(readstat_parser_t *parser) {
     if (parser) {
         if (parser->io) {